cc/trees/layer_tree_host_unittest_damage.cc - platform/external/chromium_org - Git at Google

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "cc/trees/layer_tree_host.h"

 #include "cc/test/fake_content_layer.h"
 #include "cc/test/fake_content_layer_client.h"
 #include "cc/test/fake_scrollbar_layer.h"
 #include "cc/test/layer_tree_test.h"
 #include "cc/trees/damage_tracker.h"
 #include "cc/trees/layer_tree_impl.h"

 namespace cc {
 namespace {

 // These tests deal with damage tracking.
 class LayerTreeHostDamageTest : public LayerTreeTest {};

 class LayerTreeHostDamageTestNoDamageDoesNotSwap
     : public LayerTreeHostDamageTest {
   virtual void BeginTest() OVERRIDE {
     expect_swap_and_succeed_ = 0;
     did_swaps_ = 0;
     did_swap_and_succeed_ = 0;
     PostSetNeedsCommitToMainThread();
   }

   virtual void SetupTree() OVERRIDE {
     scoped_refptr<FakeContentLayer> root = FakeContentLayer::Create(&client_);
     root->SetBounds(gfx::Size(10, 10));

     // Most of the layer isn't visible.
     content_ = FakeContentLayer::Create(&client_);
     content_->SetBounds(gfx::Size(2000, 100));
     root->AddChild(content_);

     layer_tree_host()->SetRootLayer(root);
     LayerTreeHostDamageTest::SetupTree();
   }

   virtual bool PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
                                      LayerTreeHostImpl::FrameData* frame_data,
                                      bool result) OVERRIDE {
     EXPECT_TRUE(result);

     int source_frame = host_impl->active_tree()->source_frame_number();
     switch (source_frame) {
       case 0:
         // The first frame has damage, so we should draw and swap.
         ++expect_swap_and_succeed_;
         break;
       case 1:
         // The second frame has no damage, so we should not draw and swap.
         break;
       case 2:
         // The third frame has damage again, so we should draw and swap.
         ++expect_swap_and_succeed_;
         break;
       case 3:
         // The fourth frame has no visible damage, so we should not draw and
         // swap.
         EndTest();
         break;
     }
     return result;
   }

   virtual void SwapBuffersOnThread(LayerTreeHostImpl* host_impl,
                                    bool result) OVERRIDE {
     ++did_swaps_;
     if (result)
       ++did_swap_and_succeed_;
     EXPECT_EQ(expect_swap_and_succeed_, did_swap_and_succeed_);
   }

   virtual void DidCommit() OVERRIDE {
     int next_frame = layer_tree_host()->source_frame_number();
     switch (next_frame) {
       case 1:
         layer_tree_host()->SetNeedsCommit();
         break;
       case 2:
         // Cause visible damage.
         content_->SetNeedsDisplayRect(
             gfx::Rect(layer_tree_host()->device_viewport_size()));
         break;
       case 3:
         // Cause non-visible damage.
         content_->SetNeedsDisplayRect(gfx::Rect(1990, 1990, 10, 10));
         layer_tree_host()->SetNeedsCommit();
         break;
     }
   }

   virtual void AfterTest() OVERRIDE {
     EXPECT_EQ(4, did_swaps_);
     EXPECT_EQ(2, expect_swap_and_succeed_);
     EXPECT_EQ(expect_swap_and_succeed_, did_swap_and_succeed_);
   }

   FakeContentLayerClient client_;
   scoped_refptr<FakeContentLayer> content_;
   int expect_swap_and_succeed_;
   int did_swaps_;
   int did_swap_and_succeed_;
 };

 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostDamageTestNoDamageDoesNotSwap);

 class LayerTreeHostDamageTestNoDamageReadbackDoesDraw
     : public LayerTreeHostDamageTest {
   virtual void BeginTest() OVERRIDE {
     PostSetNeedsCommitToMainThread();
   }

   virtual void SetupTree() OVERRIDE {
     scoped_refptr<FakeContentLayer> root = FakeContentLayer::Create(&client_);
     root->SetBounds(gfx::Size(10, 10));

     // Most of the layer isn't visible.
     content_ = FakeContentLayer::Create(&client_);
     content_->SetBounds(gfx::Size(100, 100));
     root->AddChild(content_);

     layer_tree_host()->SetRootLayer(root);
     LayerTreeHostDamageTest::SetupTree();
   }

   virtual bool PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
                                      LayerTreeHostImpl::FrameData* frame_data,
                                      bool result) OVERRIDE {
     EXPECT_TRUE(result);

     int source_frame = host_impl->active_tree()->source_frame_number();
     switch (source_frame) {
       case 0:
         // The first frame draws and clears any damage.
         break;
       case 1: {
         // The second frame is a readback, we should have damage in the readback
         // rect, but not swap.
         RenderSurfaceImpl* root_surface =
             host_impl->active_tree()->root_layer()->render_surface();
         gfx::RectF root_damage =
             root_surface->damage_tracker()->current_damage_rect();
         root_damage.Intersect(root_surface->content_rect());
         EXPECT_TRUE(root_damage.Contains(gfx::Rect(3, 3, 1, 1)));
         break;
       }
       case 2:
         // CompositeAndReadback causes a follow-up commit.
         break;
       case 3:
         NOTREACHED();
         break;
     }
     return result;
   }

   virtual void DidCommitAndDrawFrame() OVERRIDE {
     int next_frame = layer_tree_host()->source_frame_number();
     switch (next_frame) {
       case 1: {
         char pixels[4];
         layer_tree_host()->CompositeAndReadback(static_cast<void*>(&pixels),
                                                 gfx::Rect(3, 3, 1, 1));
         EndTest();
         break;
       }
     }
   }

   virtual void AfterTest() OVERRIDE {}

   FakeContentLayerClient client_;
   scoped_refptr<FakeContentLayer> content_;
 };

 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostDamageTestNoDamageReadbackDoesDraw);

 class LayerTreeHostDamageTestForcedFullDamage : public LayerTreeHostDamageTest {
   virtual void BeginTest() OVERRIDE {
     PostSetNeedsCommitToMainThread();
   }

   virtual void SetupTree() OVERRIDE {
     root_ = FakeContentLayer::Create(&client_);
     child_ = FakeContentLayer::Create(&client_);

     root_->SetBounds(gfx::Size(500, 500));
     child_->SetPosition(gfx::Point(100, 100));
     child_->SetBounds(gfx::Size(30, 30));

     root_->AddChild(child_);
     layer_tree_host()->SetRootLayer(root_);
     LayerTreeHostDamageTest::SetupTree();
   }

   virtual bool PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
                                      LayerTreeHostImpl::FrameData* frame_data,
                                      bool result) OVERRIDE {
     EXPECT_TRUE(result);

     RenderSurfaceImpl* root_surface =
         host_impl->active_tree()->root_layer()->render_surface();
     gfx::RectF root_damage =
         root_surface->damage_tracker()->current_damage_rect();
     root_damage.Intersect(root_surface->content_rect());

     int source_frame = host_impl->active_tree()->source_frame_number();
     switch (source_frame) {
       case 0:
         // The first frame draws and clears any damage.
         EXPECT_EQ(gfx::RectF(root_surface->content_rect()).ToString(),
                   root_damage.ToString());
         EXPECT_FALSE(frame_data->has_no_damage);
         break;
       case 1:
         // If we get a frame without damage then we don't draw.
         EXPECT_EQ(gfx::RectF().ToString(), root_damage.ToString());
         EXPECT_TRUE(frame_data->has_no_damage);

         // Then we set full damage for the next frame.
         host_impl->SetFullRootLayerDamage();
         break;
       case 2:
         // The whole frame should be damaged as requested.
         EXPECT_EQ(gfx::RectF(root_surface->content_rect()).ToString(),
                   root_damage.ToString());
         EXPECT_FALSE(frame_data->has_no_damage);

         // Just a part of the next frame should be damaged.
         child_damage_rect_ = gfx::RectF(10, 11, 12, 13);
         break;
       case 3:
         if (!delegating_renderer() &&
             !host_impl->settings().impl_side_painting) {
           // The update rect in the child should be damaged.
           // TODO(danakj): Remove this when impl side painting is always on.
           EXPECT_EQ(gfx::RectF(100+10, 100+11, 12, 13).ToString(),
                     root_damage.ToString());
         } else {
           // When using a delegating renderer, or using impl side painting, the
           // entire child is considered damaged as we need to replace its
           // resources with newly created ones.
           EXPECT_EQ(gfx::RectF(child_->position(), child_->bounds()).ToString(),
                     root_damage.ToString());
         }
         EXPECT_FALSE(frame_data->has_no_damage);

         // If we damage part of the frame, but also damage the full
         // frame, then the whole frame should be damaged.
         child_damage_rect_ = gfx::RectF(10, 11, 12, 13);
         host_impl->SetFullRootLayerDamage();
         break;
       case 4:
         // The whole frame is damaged.
         EXPECT_EQ(gfx::RectF(root_surface->content_rect()).ToString(),
                   root_damage.ToString());
         EXPECT_FALSE(frame_data->has_no_damage);

         EndTest();
         break;
     }
     return result;
   }

   virtual void DidCommitAndDrawFrame() OVERRIDE {
     if (!TestEnded())
       layer_tree_host()->SetNeedsCommit();

     if (!child_damage_rect_.IsEmpty()) {
       child_->SetNeedsDisplayRect(child_damage_rect_);
       child_damage_rect_ = gfx::RectF();
     }
   }

   virtual void AfterTest() OVERRIDE {}

   FakeContentLayerClient client_;
   scoped_refptr<FakeContentLayer> root_;
   scoped_refptr<FakeContentLayer> child_;
   gfx::RectF child_damage_rect_;
 };

 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostDamageTestForcedFullDamage);

 class LayerTreeHostDamageTestScrollbarDoesDamage
     : public LayerTreeHostDamageTest {
   virtual void BeginTest() OVERRIDE {
     did_swaps_ = 0;
     PostSetNeedsCommitToMainThread();
   }

   virtual void SetupTree() OVERRIDE {
     scoped_refptr<Layer> root_layer = Layer::Create();
     root_layer->SetBounds(gfx::Size(400,400));
     layer_tree_host()->SetRootLayer(root_layer);

     scoped_refptr<Layer> content_layer = FakeContentLayer::Create(&client_);
     content_layer->SetScrollable(true);
     content_layer->SetScrollOffset(gfx::Vector2d(10, 20));
     content_layer->SetMaxScrollOffset(gfx::Vector2d(30, 50));
     content_layer->SetBounds(gfx::Size(100, 200));
     root_layer->AddChild(content_layer);

     scoped_refptr<Layer> scrollbar_layer =
         FakeScrollbarLayer::Create(false, true, content_layer->id());
     scrollbar_layer->SetPosition(gfx::Point(300, 300));
     scrollbar_layer->SetBounds(gfx::Size(10, 100));
     root_layer->AddChild(scrollbar_layer);

     gfx::RectF content_rect(content_layer->position(),
                             content_layer->bounds());
     gfx::RectF scrollbar_rect(scrollbar_layer->position(),
                               scrollbar_layer->bounds());
     EXPECT_FALSE(content_rect.Intersects(scrollbar_rect));

     LayerTreeHostDamageTest::SetupTree();
   }

   virtual bool PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
                                      LayerTreeHostImpl::FrameData* frame_data,
                                      bool result) OVERRIDE {
     EXPECT_TRUE(result);
     RenderSurfaceImpl* root_surface =
         host_impl->active_tree()->root_layer()->render_surface();
     gfx::RectF root_damage =
         root_surface->damage_tracker()->current_damage_rect();
     root_damage.Intersect(root_surface->content_rect());
     switch (did_swaps_) {
       case 0:
         // The first frame has damage, so we should draw and swap.
         break;
       case 1:
         // The second frame should damage the scrollbars.
         EXPECT_TRUE(root_damage.Contains(gfx::Rect(300, 300, 10, 100)));
         break;
       case 2:
         // The third frame should damage the scrollbars.
         EXPECT_TRUE(root_damage.Contains(gfx::Rect(300, 300, 10, 100)));
         break;
       case 3:
         // The fourth frame should not damage the scrollbars.
         EXPECT_FALSE(root_damage.Intersects(gfx::Rect(300, 300, 10, 100)));
         EndTest();
         break;
     }
     return result;
   }

   virtual void SwapBuffersOnThread(LayerTreeHostImpl* host_impl,
                                    bool result) OVERRIDE {
     ++did_swaps_;
     EXPECT_TRUE(result);
     LayerImpl* root = host_impl->active_tree()->root_layer();
     LayerImpl* scroll_layer = root->children()[0];
     switch (did_swaps_) {
       case 1:
         host_impl->ScrollBegin(gfx::Point(1,1), InputHandler::Wheel);
         EXPECT_TRUE(host_impl->ScrollBy(gfx::Point(),
                                         gfx::Vector2dF(10.0, 10.0)));
         break;
       case 2:
         scroll_layer->SetMaxScrollOffset(gfx::Vector2d(60, 100));
         host_impl->SetNeedsRedraw();
         break;
       case 3:
         // Test that modifying the position of the content layer (not
         // scrolling) won't damage the scrollbar.
         scroll_layer->SetPosition(gfx::Point(1,1));
         scroll_layer->SetScrollOffset(scroll_layer->scroll_offset());
         host_impl->SetNeedsRedraw();
         break;
     }

   }

   virtual void AfterTest() OVERRIDE {
     EXPECT_EQ(4, did_swaps_);
   }

   FakeContentLayerClient client_;
   int did_swaps_;
 };

 MULTI_THREAD_TEST_F(LayerTreeHostDamageTestScrollbarDoesDamage);

 }  // namespace
 }  // namespace cc
	// Copyright 2012 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "cc/trees/layer_tree_host.h"

	#include "cc/test/fake_content_layer.h"
	#include "cc/test/fake_content_layer_client.h"
	#include "cc/test/fake_scrollbar_layer.h"
	#include "cc/test/layer_tree_test.h"
	#include "cc/trees/damage_tracker.h"
	#include "cc/trees/layer_tree_impl.h"

	namespace cc {
	namespace {

	// These tests deal with damage tracking.
	class LayerTreeHostDamageTest : public LayerTreeTest {};

	class LayerTreeHostDamageTestNoDamageDoesNotSwap
	: public LayerTreeHostDamageTest {
	virtual void BeginTest() OVERRIDE {
	expect_swap_and_succeed_ = 0;
	did_swaps_ = 0;
	did_swap_and_succeed_ = 0;
	PostSetNeedsCommitToMainThread();
	}

	virtual void SetupTree() OVERRIDE {
	scoped_refptr<FakeContentLayer> root = FakeContentLayer::Create(&client_);
	root->SetBounds(gfx::Size(10, 10));

	// Most of the layer isn't visible.
	content_ = FakeContentLayer::Create(&client_);
	content_->SetBounds(gfx::Size(2000, 100));
	root->AddChild(content_);

	layer_tree_host()->SetRootLayer(root);
	LayerTreeHostDamageTest::SetupTree();
	}

	virtual bool PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
	LayerTreeHostImpl::FrameData* frame_data,
	bool result) OVERRIDE {
	EXPECT_TRUE(result);

	int source_frame = host_impl->active_tree()->source_frame_number();
	switch (source_frame) {
	case 0:
	// The first frame has damage, so we should draw and swap.
	++expect_swap_and_succeed_;
	break;
	case 1:
	// The second frame has no damage, so we should not draw and swap.
	break;
	case 2:
	// The third frame has damage again, so we should draw and swap.
	++expect_swap_and_succeed_;
	break;
	case 3:
	// The fourth frame has no visible damage, so we should not draw and
	// swap.
	EndTest();
	break;
	}
	return result;
	}

	virtual void SwapBuffersOnThread(LayerTreeHostImpl* host_impl,
	bool result) OVERRIDE {
	++did_swaps_;
	if (result)
	++did_swap_and_succeed_;
	EXPECT_EQ(expect_swap_and_succeed_, did_swap_and_succeed_);
	}

	virtual void DidCommit() OVERRIDE {
	int next_frame = layer_tree_host()->source_frame_number();
	switch (next_frame) {
	case 1:
	layer_tree_host()->SetNeedsCommit();
	break;
	case 2:
	// Cause visible damage.
	content_->SetNeedsDisplayRect(
	gfx::Rect(layer_tree_host()->device_viewport_size()));
	break;
	case 3:
	// Cause non-visible damage.
	content_->SetNeedsDisplayRect(gfx::Rect(1990, 1990, 10, 10));
	layer_tree_host()->SetNeedsCommit();
	break;
	}
	}

	virtual void AfterTest() OVERRIDE {
	EXPECT_EQ(4, did_swaps_);
	EXPECT_EQ(2, expect_swap_and_succeed_);
	EXPECT_EQ(expect_swap_and_succeed_, did_swap_and_succeed_);
	}

	FakeContentLayerClient client_;
	scoped_refptr<FakeContentLayer> content_;
	int expect_swap_and_succeed_;
	int did_swaps_;
	int did_swap_and_succeed_;
	};

	SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostDamageTestNoDamageDoesNotSwap);

	class LayerTreeHostDamageTestNoDamageReadbackDoesDraw
	: public LayerTreeHostDamageTest {
	virtual void BeginTest() OVERRIDE {
	PostSetNeedsCommitToMainThread();
	}

	virtual void SetupTree() OVERRIDE {
	scoped_refptr<FakeContentLayer> root = FakeContentLayer::Create(&client_);
	root->SetBounds(gfx::Size(10, 10));

	// Most of the layer isn't visible.
	content_ = FakeContentLayer::Create(&client_);
	content_->SetBounds(gfx::Size(100, 100));
	root->AddChild(content_);

	layer_tree_host()->SetRootLayer(root);
	LayerTreeHostDamageTest::SetupTree();
	}

	virtual bool PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
	LayerTreeHostImpl::FrameData* frame_data,
	bool result) OVERRIDE {
	EXPECT_TRUE(result);

	int source_frame = host_impl->active_tree()->source_frame_number();
	switch (source_frame) {
	case 0:
	// The first frame draws and clears any damage.
	break;
	case 1: {
	// The second frame is a readback, we should have damage in the readback
	// rect, but not swap.
	RenderSurfaceImpl* root_surface =
	host_impl->active_tree()->root_layer()->render_surface();
	gfx::RectF root_damage =
	root_surface->damage_tracker()->current_damage_rect();
	root_damage.Intersect(root_surface->content_rect());
	EXPECT_TRUE(root_damage.Contains(gfx::Rect(3, 3, 1, 1)));
	break;
	}
	case 2:
	// CompositeAndReadback causes a follow-up commit.
	break;
	case 3:
	NOTREACHED();
	break;
	}
	return result;
	}

	virtual void DidCommitAndDrawFrame() OVERRIDE {
	int next_frame = layer_tree_host()->source_frame_number();
	switch (next_frame) {
	case 1: {
	char pixels[4];
	layer_tree_host()->CompositeAndReadback(static_cast<void*>(&pixels),
	gfx::Rect(3, 3, 1, 1));
	EndTest();
	break;
	}
	}
	}

	virtual void AfterTest() OVERRIDE {}

	FakeContentLayerClient client_;
	scoped_refptr<FakeContentLayer> content_;
	};

	SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostDamageTestNoDamageReadbackDoesDraw);

	class LayerTreeHostDamageTestForcedFullDamage : public LayerTreeHostDamageTest {
	virtual void BeginTest() OVERRIDE {
	PostSetNeedsCommitToMainThread();
	}

	virtual void SetupTree() OVERRIDE {
	root_ = FakeContentLayer::Create(&client_);
	child_ = FakeContentLayer::Create(&client_);

	root_->SetBounds(gfx::Size(500, 500));
	child_->SetPosition(gfx::Point(100, 100));
	child_->SetBounds(gfx::Size(30, 30));

	root_->AddChild(child_);
	layer_tree_host()->SetRootLayer(root_);
	LayerTreeHostDamageTest::SetupTree();
	}

	virtual bool PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
	LayerTreeHostImpl::FrameData* frame_data,
	bool result) OVERRIDE {
	EXPECT_TRUE(result);

	RenderSurfaceImpl* root_surface =
	host_impl->active_tree()->root_layer()->render_surface();
	gfx::RectF root_damage =
	root_surface->damage_tracker()->current_damage_rect();
	root_damage.Intersect(root_surface->content_rect());

	int source_frame = host_impl->active_tree()->source_frame_number();
	switch (source_frame) {
	case 0:
	// The first frame draws and clears any damage.
	EXPECT_EQ(gfx::RectF(root_surface->content_rect()).ToString(),
	root_damage.ToString());
	EXPECT_FALSE(frame_data->has_no_damage);
	break;
	case 1:
	// If we get a frame without damage then we don't draw.
	EXPECT_EQ(gfx::RectF().ToString(), root_damage.ToString());
	EXPECT_TRUE(frame_data->has_no_damage);

	// Then we set full damage for the next frame.
	host_impl->SetFullRootLayerDamage();
	break;
	case 2:
	// The whole frame should be damaged as requested.
	EXPECT_EQ(gfx::RectF(root_surface->content_rect()).ToString(),
	root_damage.ToString());
	EXPECT_FALSE(frame_data->has_no_damage);

	// Just a part of the next frame should be damaged.
	child_damage_rect_ = gfx::RectF(10, 11, 12, 13);
	break;
	case 3:
	if (!delegating_renderer() &&
	!host_impl->settings().impl_side_painting) {
	// The update rect in the child should be damaged.
	// TODO(danakj): Remove this when impl side painting is always on.
	EXPECT_EQ(gfx::RectF(100+10, 100+11, 12, 13).ToString(),
	root_damage.ToString());
	} else {
	// When using a delegating renderer, or using impl side painting, the
	// entire child is considered damaged as we need to replace its
	// resources with newly created ones.
	EXPECT_EQ(gfx::RectF(child_->position(), child_->bounds()).ToString(),
	root_damage.ToString());
	}
	EXPECT_FALSE(frame_data->has_no_damage);

	// If we damage part of the frame, but also damage the full
	// frame, then the whole frame should be damaged.
	child_damage_rect_ = gfx::RectF(10, 11, 12, 13);
	host_impl->SetFullRootLayerDamage();
	break;
	case 4:
	// The whole frame is damaged.
	EXPECT_EQ(gfx::RectF(root_surface->content_rect()).ToString(),
	root_damage.ToString());
	EXPECT_FALSE(frame_data->has_no_damage);

	EndTest();
	break;
	}
	return result;
	}

	virtual void DidCommitAndDrawFrame() OVERRIDE {
	if (!TestEnded())
	layer_tree_host()->SetNeedsCommit();

	if (!child_damage_rect_.IsEmpty()) {
	child_->SetNeedsDisplayRect(child_damage_rect_);
	child_damage_rect_ = gfx::RectF();
	}
	}

	virtual void AfterTest() OVERRIDE {}

	FakeContentLayerClient client_;
	scoped_refptr<FakeContentLayer> root_;
	scoped_refptr<FakeContentLayer> child_;
	gfx::RectF child_damage_rect_;
	};

	SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostDamageTestForcedFullDamage);

	class LayerTreeHostDamageTestScrollbarDoesDamage
	: public LayerTreeHostDamageTest {
	virtual void BeginTest() OVERRIDE {
	did_swaps_ = 0;
	PostSetNeedsCommitToMainThread();
	}

	virtual void SetupTree() OVERRIDE {
	scoped_refptr<Layer> root_layer = Layer::Create();
	root_layer->SetBounds(gfx::Size(400,400));
	layer_tree_host()->SetRootLayer(root_layer);

	scoped_refptr<Layer> content_layer = FakeContentLayer::Create(&client_);
	content_layer->SetScrollable(true);
	content_layer->SetScrollOffset(gfx::Vector2d(10, 20));
	content_layer->SetMaxScrollOffset(gfx::Vector2d(30, 50));
	content_layer->SetBounds(gfx::Size(100, 200));
	root_layer->AddChild(content_layer);

	scoped_refptr<Layer> scrollbar_layer =
	FakeScrollbarLayer::Create(false, true, content_layer->id());
	scrollbar_layer->SetPosition(gfx::Point(300, 300));
	scrollbar_layer->SetBounds(gfx::Size(10, 100));
	root_layer->AddChild(scrollbar_layer);

	gfx::RectF content_rect(content_layer->position(),
	content_layer->bounds());
	gfx::RectF scrollbar_rect(scrollbar_layer->position(),
	scrollbar_layer->bounds());
	EXPECT_FALSE(content_rect.Intersects(scrollbar_rect));

	LayerTreeHostDamageTest::SetupTree();
	}

	virtual bool PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
	LayerTreeHostImpl::FrameData* frame_data,
	bool result) OVERRIDE {
	EXPECT_TRUE(result);
	RenderSurfaceImpl* root_surface =
	host_impl->active_tree()->root_layer()->render_surface();
	gfx::RectF root_damage =
	root_surface->damage_tracker()->current_damage_rect();
	root_damage.Intersect(root_surface->content_rect());
	switch (did_swaps_) {
	case 0:
	// The first frame has damage, so we should draw and swap.
	break;
	case 1:
	// The second frame should damage the scrollbars.
	EXPECT_TRUE(root_damage.Contains(gfx::Rect(300, 300, 10, 100)));
	break;
	case 2:
	// The third frame should damage the scrollbars.
	EXPECT_TRUE(root_damage.Contains(gfx::Rect(300, 300, 10, 100)));
	break;
	case 3:
	// The fourth frame should not damage the scrollbars.
	EXPECT_FALSE(root_damage.Intersects(gfx::Rect(300, 300, 10, 100)));
	EndTest();
	break;
	}
	return result;
	}

	virtual void SwapBuffersOnThread(LayerTreeHostImpl* host_impl,
	bool result) OVERRIDE {
	++did_swaps_;
	EXPECT_TRUE(result);
	LayerImpl* root = host_impl->active_tree()->root_layer();
	LayerImpl* scroll_layer = root->children()[0];
	switch (did_swaps_) {
	case 1:
	host_impl->ScrollBegin(gfx::Point(1,1), InputHandler::Wheel);
	EXPECT_TRUE(host_impl->ScrollBy(gfx::Point(),
	gfx::Vector2dF(10.0, 10.0)));
	break;
	case 2:
	scroll_layer->SetMaxScrollOffset(gfx::Vector2d(60, 100));
	host_impl->SetNeedsRedraw();
	break;
	case 3:
	// Test that modifying the position of the content layer (not
	// scrolling) won't damage the scrollbar.
	scroll_layer->SetPosition(gfx::Point(1,1));
	scroll_layer->SetScrollOffset(scroll_layer->scroll_offset());
	host_impl->SetNeedsRedraw();
	break;
	}

	}

	virtual void AfterTest() OVERRIDE {
	EXPECT_EQ(4, did_swaps_);
	}

	FakeContentLayerClient client_;
	int did_swaps_;
	};

	MULTI_THREAD_TEST_F(LayerTreeHostDamageTestScrollbarDoesDamage);

	} // namespace
	} // namespace cc