Reland "Distinguish warm/hot launch by whether the activity has attached process"

If the process of an activity was died in background, its activity and
task record will still be in history stack. If the process is started
again in background such as receiving broadcast. Then the launch of the
same activity will have the conditions: process exists and the result
code is START_TASK_TO_FRONT. But the activity still need to create so
it should be warm launch.

This reverts commit 3a1f6225c29136292f087a131250d730c2712695.
Reason for revert: remove redundant "notifyWindowsDrawn(mTopActivity)"
in test case that was missed when resolving conflict.

Bug: 171549711
Test: ActivityMetricsLaunchObserverTests#testOnActivityLaunchFinished
Change-Id: I43625184392c22e6769a147beda4817f70afcf9a
Merged-In: I2b8e45ddfd76ce4fb0fdb0c244a8f4170fbabd21
diff --git a/services/core/java/com/android/server/wm/ActivityMetricsLogger.java b/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
index 189b21f..5570c01 100644
--- a/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
+++ b/services/core/java/com/android/server/wm/ActivityMetricsLogger.java
@@ -129,7 +129,6 @@
      */
     private static final int IGNORE_CALLER = -1;
     private static final int INVALID_DELAY = -1;
-    private static final int INVALID_TRANSITION_TYPE = -1;
 
     // Preallocated strings we are sending to tron, so we don't have to allocate a new one every
     // time we log.
@@ -224,22 +223,19 @@
         static TransitionInfo create(@NonNull ActivityRecord r,
                 @NonNull LaunchingState launchingState, boolean processRunning,
                 boolean processSwitch, int startResult) {
-            int transitionType = INVALID_TRANSITION_TYPE;
+            if (startResult != START_SUCCESS && startResult != START_TASK_TO_FRONT) {
+                return null;
+            }
+            final int transitionType;
             if (processRunning) {
-                if (startResult == START_SUCCESS) {
-                    transitionType = TYPE_TRANSITION_WARM_LAUNCH;
-                } else if (startResult == START_TASK_TO_FRONT) {
-                    transitionType = TYPE_TRANSITION_HOT_LAUNCH;
-                }
-            } else if (startResult == START_SUCCESS || startResult == START_TASK_TO_FRONT) {
+                transitionType = r.attachedToProcess()
+                        ? TYPE_TRANSITION_HOT_LAUNCH
+                        : TYPE_TRANSITION_WARM_LAUNCH;
+            } else {
                 // Task may still exist when cold launching an activity and the start result will be
                 // set to START_TASK_TO_FRONT. Treat this as a COLD launch.
                 transitionType = TYPE_TRANSITION_COLD_LAUNCH;
             }
-            if (transitionType == INVALID_TRANSITION_TYPE) {
-                // That means the startResult is neither START_SUCCESS nor START_TASK_TO_FRONT.
-                return null;
-            }
             return new TransitionInfo(r, launchingState, transitionType, processRunning,
                     processSwitch);
         }
diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java
index e1ce431f..5b516a9 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java
@@ -32,6 +32,7 @@
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.timeout;
 
+import android.app.WaitResult;
 import android.content.Intent;
 import android.os.SystemClock;
 import android.platform.test.annotations.Presubmit;
@@ -163,10 +164,15 @@
 
     @Test
     public void testOnActivityLaunchFinished() {
+        // Assume that the process is started (ActivityBuilder has mocked the returned value of
+        // ATMS#getProcessController) but the activity has not attached process.
+        mTopActivity.app = null;
         onActivityLaunched(mTopActivity);
 
         notifyTransitionStarting(mTopActivity);
-        notifyWindowsDrawn(mTopActivity);
+        final ActivityMetricsLogger.TransitionInfoSnapshot info = notifyWindowsDrawn(mTopActivity);
+        assertWithMessage("Warm launch").that(info.getLaunchState())
+                .isEqualTo(WaitResult.LAUNCH_STATE_WARM);
 
         verifyOnActivityLaunchFinished(mTopActivity);
         verifyNoMoreInteractions(mLaunchObserver);
@@ -201,7 +207,7 @@
         notifyActivityLaunching(noDrawnActivity.intent);
         notifyActivityLaunched(START_SUCCESS, noDrawnActivity);
 
-        noDrawnActivity.destroyIfPossible("test");
+        noDrawnActivity.mVisibleRequested = false;
         mActivityMetricsLogger.notifyVisibilityChanged(noDrawnActivity);
 
         verifyAsync(mLaunchObserver).onActivityLaunchCancelled(eqProto(noDrawnActivity));
@@ -216,7 +222,9 @@
         mActivityMetricsLogger.logAppTransitionReportedDrawn(mTopActivity, false);
         notifyTransitionStarting(mTopActivity);
         // The pending fully drawn event should send when the actual windows drawn event occurs.
-        notifyWindowsDrawn(mTopActivity);
+        final ActivityMetricsLogger.TransitionInfoSnapshot info = notifyWindowsDrawn(mTopActivity);
+        assertWithMessage("Hot launch").that(info.getLaunchState())
+                .isEqualTo(WaitResult.LAUNCH_STATE_HOT);
 
         verifyAsync(mLaunchObserver).onReportFullyDrawn(eqProto(mTopActivity), anyLong());
         verifyOnActivityLaunchFinished(mTopActivity);
@@ -260,8 +268,8 @@
         mActivityMetricsLogger.notifyTransitionStarting(reasons);
     }
 
-    private void notifyWindowsDrawn(ActivityRecord r) {
-        mActivityMetricsLogger.notifyWindowsDrawn(r, SystemClock.elapsedRealtimeNanos());
+    private ActivityMetricsLogger.TransitionInfoSnapshot notifyWindowsDrawn(ActivityRecord r) {
+        return mActivityMetricsLogger.notifyWindowsDrawn(r, SystemClock.elapsedRealtimeNanos());
     }
 
     @Test