From b7850d11ba8901c29b3303e4b2f7800d310fe8ce Mon Sep 17 00:00:00 2001
From: Botond Ballo <botond@mozilla.com>
Date: Thu, 22 May 2014 17:17:39 -0400
Subject: [PATCH] Bug 998025 - Have APZ gtests clear the overscroll handoff
 chain when appropriate. r=kats

--HG--
extra : rebase_source : 8253d35c2e0c610398c6b0d3f812552d0a09c246
---
 gfx/layers/apz/src/APZCTreeManager.h           | 6 +++++-
 gfx/tests/gtest/TestAsyncPanZoomController.cpp | 9 ++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/gfx/layers/apz/src/APZCTreeManager.h b/gfx/layers/apz/src/APZCTreeManager.h
index da5e9e7e697..7e2783ed468 100644
--- a/gfx/layers/apz/src/APZCTreeManager.h
+++ b/gfx/layers/apz/src/APZCTreeManager.h
@@ -303,6 +303,11 @@ protected:
    * Build the chain of APZCs that will handle overscroll for a pan starting at |aInitialTarget|.
    */
   void BuildOverscrollHandoffChain(const nsRefPtr<AsyncPanZoomController>& aInitialTarget);
+
+  /*
+   * Clear the handoff chain built in BuildOverscrollHandoffChain().
+   */
+  void ClearOverscrollHandoffChain();
 public:
   /* Some helper functions to find an APZC given some identifying input. These functions
      lock the tree of APZCs while they find the right one, and then return an addref'd
@@ -332,7 +337,6 @@ private:
                              ScrollableLayerGuid* aOutTargetGuid);
   void UpdateZoomConstraintsRecursively(AsyncPanZoomController* aApzc,
                                         const ZoomConstraints& aConstraints);
-  void ClearOverscrollHandoffChain();
 
   /**
    * Recursive helper function to build the APZC tree. The tree of APZC instances has
diff --git a/gfx/tests/gtest/TestAsyncPanZoomController.cpp b/gfx/tests/gtest/TestAsyncPanZoomController.cpp
index c1ccde5a58a..5c3c69bab05 100644
--- a/gfx/tests/gtest/TestAsyncPanZoomController.cpp
+++ b/gfx/tests/gtest/TestAsyncPanZoomController.cpp
@@ -143,10 +143,13 @@ public:
 
 class TestAPZCTreeManager : public APZCTreeManager {
 public:
-  // Expose this so test code can call it directly.
+  // Expose these so test code can call it directly.
   void BuildOverscrollHandoffChain(AsyncPanZoomController* aApzc) {
     APZCTreeManager::BuildOverscrollHandoffChain(aApzc);
   }
+  void ClearOverscrollHandoffChain() {
+    APZCTreeManager::ClearOverscrollHandoffChain();
+  }
 };
 
 static
@@ -235,6 +238,10 @@ void ApzcPan(AsyncPanZoomController* apzc,
   aTime += TIME_BETWEEN_TOUCH_EVENT;
   mti.mTouches.AppendElement(SingleTouchData(0, ScreenIntPoint(10, aTouchEndY), ScreenSize(0, 0), 0, 0));
   status = apzc->ReceiveInputEvent(mti);
+
+  // Since we've explicitly built the overscroll handoff chain before
+  // touch-start, we need to explicitly clear it after touch-end.
+  aTreeManager->ClearOverscrollHandoffChain();
 }
 
 static