Defer flushing the touch queue when all touch handlers removed

content/browser/renderer_host/input/input_router_impl_unittest.cc

Index: content/browser/renderer_host/input/input_router_impl_unittest.cc
diff --git a/content/browser/renderer_host/input/input_router_impl_unittest.cc b/content/browser/renderer_host/input/input_router_impl_unittest.cc
index 713ae5f84577f817a9f99f6e05e9b3a3d601a0f1..b3a535ffe819b1fd4aadae28ed62a023574f5166 100644
--- a/content/browser/renderer_host/input/input_router_impl_unittest.cc
+++ b/content/browser/renderer_host/input/input_router_impl_unittest.cc
@@ -619,8 +619,8 @@ TEST_F(InputRouterImplTest, TouchEventQueue) {
   EXPECT_EQ(0U, GetSentMessageCountAndResetSink());
 }
 
-// Tests that the touch-queue is emptied if a page stops listening for touch
-// events.
+// Tests that the touch-queue is emptied after a page stops listening for touch
+// events and the outstanding ack is received.
 TEST_F(InputRouterImplTest, TouchEventQueueFlush) {
   OnHasTouchEventHandlers(true);
   EXPECT_TRUE(client_->has_touch_handler());
@@ -632,15 +632,23 @@ TEST_F(InputRouterImplTest, TouchEventQueueFlush) {
   // Send a touch-press event.
   PressTouchPoint(1, 1);
   SendTouchEvent();
+  MoveTouchPoint(0, 2, 2);
+  MoveTouchPoint(0, 3, 3);
   EXPECT_FALSE(TouchEventQueueEmpty());
   EXPECT_EQ(1U, GetSentMessageCountAndResetSink());
 
-  // The page stops listening for touch-events. The touch-event queue should now
-  // be emptied, but none of the queued touch-events should be sent to the
-  // renderer.
+  // The page stops listening for touch-events. Note that flushing is deferred
+  // until the outstanding ack is received.
   OnHasTouchEventHandlers(false);
   EXPECT_FALSE(client_->has_touch_handler());
   EXPECT_EQ(0U, GetSentMessageCountAndResetSink());
+  EXPECT_FALSE(TouchEventQueueEmpty());
+  EXPECT_TRUE(input_router_->ShouldForwardTouchEvent());
+
+  // After the ack, the touch-event queue should be empty, and none of the
+  // flushed touch-events should have been sent to the renderer.
+  SendInputEventACK(WebInputEvent::TouchStart, INPUT_EVENT_ACK_STATE_CONSUMED);
+  EXPECT_EQ(0U, GetSentMessageCountAndResetSink());
   EXPECT_TRUE(TouchEventQueueEmpty());
   EXPECT_FALSE(input_router_->ShouldForwardTouchEvent());
 }