Properly clear textures for Hardware Bitmaps

Test: manual  (Description in the bug)
bug:34858530
Change-Id: I13eb89077c43ca28436509a7af5b7c11374446c4
(cherry picked from commit 83809fec686b47da73ee0aaa80d226de7e33aab9)
diff --git a/libs/hwui/Android.mk b/libs/hwui/Android.mk
index 138a5ef..a799fdf 100644
--- a/libs/hwui/Android.mk
+++ b/libs/hwui/Android.mk
@@ -316,6 +316,7 @@
     tests/unit/StringUtilsTests.cpp \
     tests/unit/TestUtilsTests.cpp \
     tests/unit/TextDropShadowCacheTests.cpp \
+    tests/unit/TextureCacheTests.cpp \
     tests/unit/VectorDrawableTests.cpp \
 
 include $(LOCAL_PATH)/hwui_static_deps.mk
diff --git a/libs/hwui/TextureCache.cpp b/libs/hwui/TextureCache.cpp
index 1aeb8d6..63a6a2c 100644
--- a/libs/hwui/TextureCache.cpp
+++ b/libs/hwui/TextureCache.cpp
@@ -46,7 +46,7 @@
 }
 
 TextureCache::~TextureCache() {
-    mCache.clear();
+    this->clear();
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -214,6 +214,10 @@
 
 void TextureCache::clear() {
     mCache.clear();
+    for(auto& iter: mHardwareTextures) {
+        iter.second->deleteTexture();
+    }
+    mHardwareTextures.clear();
     TEXTURE_LOGD("TextureCache:clear(), mSize = %d", mSize);
 }
 
diff --git a/libs/hwui/debug/nullegl.cpp b/libs/hwui/debug/nullegl.cpp
index 1ce180d..2ae71df 100644
--- a/libs/hwui/debug/nullegl.cpp
+++ b/libs/hwui/debug/nullegl.cpp
@@ -22,6 +22,7 @@
 #include <string.h>
 
 static EGLDisplay gDisplay = (EGLDisplay) 1;
+static EGLSyncKHR gFence = (EGLSyncKHR) 1;
 
 typedef struct {
     EGLSurface surface;
@@ -159,6 +160,18 @@
     return (EGLImageKHR) malloc(sizeof(EGLImageKHR));
 }
 
+EGLSyncKHR eglCreateSyncKHR(EGLDisplay dpy, EGLenum type, const EGLint *attrib_list) {
+    return gFence;
+}
+
+EGLBoolean eglDestroySyncKHR(EGLDisplay dpy, EGLSyncKHR sync) {
+    return EGL_TRUE;
+}
+
+EGLint eglClientWaitSyncKHR(EGLDisplay dpy, EGLSyncKHR sync, EGLint flags, EGLTimeKHR timeout) {
+    return EGL_CONDITION_SATISFIED_KHR;
+}
+
 EGLBoolean eglDestroyImageKHR(EGLDisplay dpy, EGLImageKHR image) {
     free(image);
     return EGL_TRUE;
diff --git a/libs/hwui/tests/unit/TextureCacheTests.cpp b/libs/hwui/tests/unit/TextureCacheTests.cpp
new file mode 100644
index 0000000..72384bf
--- /dev/null
+++ b/libs/hwui/tests/unit/TextureCacheTests.cpp
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+
+#include "Extensions.h"
+#include "TextureCache.h"
+#include "tests/common/TestUtils.h"
+
+using namespace android;
+using namespace android::uirenderer;
+
+RENDERTHREAD_OPENGL_PIPELINE_TEST(TextureCache, clear) {
+    TextureCache cache;
+    ASSERT_EQ(cache.getSize(), 0u);
+    // it is not 0, because FontRenderer allocates one texture
+    int initialCount = GpuMemoryTracker::getInstanceCount(GpuObjectType::Texture);
+    SkBitmap skBitmap;
+    SkImageInfo info = SkImageInfo::Make(100, 100, kN32_SkColorType, kPremul_SkAlphaType);
+    skBitmap.setInfo(info);
+    sk_sp<Bitmap> hwBitmap(Bitmap::allocateHardwareBitmap(renderThread, skBitmap));
+    cache.get(hwBitmap.get());
+    ASSERT_EQ(GpuMemoryTracker::getInstanceCount(GpuObjectType::Texture), initialCount + 1);
+    cache.clear();
+    ASSERT_EQ(GpuMemoryTracker::getInstanceCount(GpuObjectType::Texture), initialCount);
+}