Simplify the consume before traversal heuristic.

Calling doConsumeBatchedInput() from doTraversals() can result
in redundant attempts to consume batched input.  Instead of making
this call directly, just schedule consume batched input at the
same time as traversals are scheduled.  This should have the same
overall effect.

Bug: 6375101
Change-Id: Ie5799e6a68fedbd1978cca6d03852d9a7f1b1f64

Author: Jeff Brown

core/java/android/view/ViewRootImpl.java

@@ -947,6 +947,7 @@ void scheduleTraversals() {
             mTraversalBarrier = mHandler.getLooper().postSyncBarrier();
             mChoreographer.postCallback(
                     Choreographer.CALLBACK_TRAVERSAL, mTraversalRunnable, null);
+            scheduleConsumeBatchedInput();
         }
     }
 
@@ -964,9 +965,6 @@ void doTraversal() {
             mTraversalScheduled = false;
             mHandler.getLooper().removeSyncBarrier(mTraversalBarrier);
 
-            doConsumeBatchedInput(false);
-            doProcessInputEvents();
-
             if (mProfile) {
                 Debug.startMethodTracing("ViewAncestor");
             }
@@ -4206,20 +4204,13 @@ void unscheduleConsumeBatchedInput() {
         }
     }
 
-    void doConsumeBatchedInput(boolean callback) {
+    void doConsumeBatchedInput() {
         if (mConsumeBatchedInputScheduled) {
             mConsumeBatchedInputScheduled = false;
-            if (!callback) {
-                mChoreographer.removeCallbacks(Choreographer.CALLBACK_INPUT,
-                        mConsumedBatchedInputRunnable, null);
+            if (mInputEventReceiver != null) {
+                mInputEventReceiver.consumeBatchedInputEvents();
             }
-        }
-
-        // Always consume batched input events even if not scheduled, because there
-        // might be new input there waiting for us that we have no noticed yet because
-        // the Looper has not had a chance to run again.
-        if (mInputEventReceiver != null) {
-            mInputEventReceiver.consumeBatchedInputEvents();
+            doProcessInputEvents();
         }
     }
 
@@ -4257,8 +4248,7 @@ public void dispose() {
     final class ConsumeBatchedInputRunnable implements Runnable {
         @Override
         public void run() {
-            doConsumeBatchedInput(true);
-            doProcessInputEvents();
+            doConsumeBatchedInput();
         }
     }
     final ConsumeBatchedInputRunnable mConsumedBatchedInputRunnable =