Bug 868047 - Use a PresShell ID to eliminate stale APZC events; r=roc,benwa

CLOBBER

@@ -17,7 +17,7 @@
 #
 # Modifying this file will now automatically clobber the buildbot machines \o/
 #
-Bug 874640 touched webidl, so Windows needs to clobber
+Bug 868047 - Adding a field to FrameMetrics affects ContainerLayer class size
 
 Alternative to clobber is to run ./config.status from the objdir and to
 touch the CLOBBER file in the objdir.

dom/base/nsDOMWindowUtils.cpp

@@ -522,6 +522,21 @@ nsDOMWindowUtils::GetIsFirstPaint(bool *aIsFirstPaint)
   return NS_ERROR_FAILURE;
 }
 
+NS_IMETHODIMP
+nsDOMWindowUtils::GetPresShellId(uint32_t *aPresShellId)
+{
+  if (!nsContentUtils::IsCallerChrome()) {
+    return NS_ERROR_DOM_SECURITY_ERR;
+  }
+
+  nsIPresShell* presShell = GetPresShell();
+  if (presShell) {
+    *aPresShellId = presShell->GetPresShellId();
+    return NS_OK;
+  }
+  return NS_ERROR_FAILURE;
+}
+
 /* static */
 mozilla::widget::Modifiers
 nsDOMWindowUtils::GetWidgetModifiers(int32_t aModifiers)

dom/interfaces/base/nsIDOMWindowUtils.idl

@@ -195,6 +195,8 @@ interface nsIDOMWindowUtils : nsISupports {
    */
   attribute boolean isFirstPaint;
 
+  void getPresShellId(out uint32_t aPresShellId);
+
   /**
    * Following modifiers are for sent*Event() except sendNative*Event().
    * NOTE: MODIFIER_ALT, MODIFIER_CONTROL, MODIFIER_SHIFT and MODIFIER_META

dom/ipc/TabChild.cpp

@@ -633,7 +633,7 @@ TabChild::HandlePossibleViewportChange()
 
   // Force a repaint with these metrics. This, among other things, sets the
   // displayport, so we start with async painting.
-  RecvUpdateFrame(metrics);
+  ProcessUpdateFrame(metrics);
 }
 
 nsresult
@@ -1454,6 +1454,20 @@ ScrollWindowTo(nsIDOMWindow* aWindow, const mozilla::gfx::Point& aPoint)
 bool
 TabChild::RecvUpdateFrame(const FrameMetrics& aFrameMetrics)
 {
+    nsCOMPtr<nsIDOMWindowUtils> utils(GetDOMWindowUtils());
+
+    uint32_t presShellId;
+    nsresult rv = utils->GetPresShellId(&presShellId);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    if (NS_SUCCEEDED(rv) && aFrameMetrics.mPresShellId != presShellId) {
+        return true;
+    }
+    return ProcessUpdateFrame(aFrameMetrics);
+}
+
+bool
+TabChild::ProcessUpdateFrame(const FrameMetrics& aFrameMetrics)
+  {
     if (!mCx || !mTabChildGlobal) {
         return true;
     }

dom/ipc/TabChild.h

@@ -366,6 +366,7 @@ private:
     bool InitRenderingState();
     void DestroyWindow();
     void SetProcessNameToAppName();
+    bool ProcessUpdateFrame(const mozilla::layers::FrameMetrics& aFrameMetrics);
 
     // Call RecvShow(nsIntSize(0, 0)) and block future calls to RecvShow().
     void DoFakeShow();

gfx/layers/FrameMetrics.h

@@ -42,6 +42,7 @@ public:
     , mZoom(1, 1)
     , mDevPixelsPerCSSPixel(1)
     , mMayHaveTouchListeners(false)
+    , mPresShellId(-1)
   {}
 
   // Default copy ctor and operator= are fine
@@ -58,7 +59,8 @@ public:
            mScrollableRect.IsEqualEdges(aOther.mScrollableRect) &&
            mResolution == aOther.mResolution &&
            mDevPixelsPerCSSPixel == aOther.mDevPixelsPerCSSPixel &&
-           mMayHaveTouchListeners == aOther.mMayHaveTouchListeners;
+           mMayHaveTouchListeners == aOther.mMayHaveTouchListeners &&
+           mPresShellId == aOther.mPresShellId;
   }
   bool operator!=(const FrameMetrics& aOther) const
   {
@@ -67,7 +69,10 @@ public:
 
   bool IsDefault() const
   {
-    return (FrameMetrics() == *this);
+    FrameMetrics def;
+
+    def.mPresShellId = mPresShellId;
+    return (def == *this);
   }
 
   bool IsRootScrollable() const
@@ -241,6 +246,8 @@ public:
 
   // Whether or not this frame may have touch listeners.
   bool mMayHaveTouchListeners;
+
+  uint32_t mPresShellId;
 };
 
 }

ipc/glue/IPCMessageUtils.h

@@ -1044,6 +1044,7 @@ struct ParamTraits<mozilla::layers::FrameMetrics>
     WriteParam(aMsg, aParam.mZoom);
     WriteParam(aMsg, aParam.mDevPixelsPerCSSPixel);
     WriteParam(aMsg, aParam.mMayHaveTouchListeners);
+    WriteParam(aMsg, aParam.mPresShellId);
   }
 
   static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
@@ -1059,7 +1060,8 @@ struct ParamTraits<mozilla::layers::FrameMetrics>
             ReadParam(aMsg, aIter, &aResult->mResolution) &&
             ReadParam(aMsg, aIter, &aResult->mZoom) &&
             ReadParam(aMsg, aIter, &aResult->mDevPixelsPerCSSPixel) &&
-            ReadParam(aMsg, aIter, &aResult->mMayHaveTouchListeners));
+            ReadParam(aMsg, aIter, &aResult->mMayHaveTouchListeners) &&
+            ReadParam(aMsg, aIter, &aResult->mPresShellId));
   }
 };
 

layout/base/nsDisplayList.cpp

@@ -695,6 +695,8 @@ static void RecordFrameMetrics(nsIFrame* aForFrame,
     widget->GetBounds(metrics.mCompositionBounds);
   }
 
+  metrics.mPresShellId = presShell->GetPresShellId();
+
   aRoot->SetFrameMetrics(metrics);
 }
 

layout/base/nsIPresShell.h

@@ -1229,6 +1229,8 @@ public:
    */
   bool GetIsFirstPaint() const { return mIsFirstPaint; }
 
+  uint32_t GetPresShellId() { return mPresShellId; }
+
   /**
    * Dispatch a mouse move event based on the most recent mouse position if
    * this PresShell is visible. This is used when the contents of the page
@@ -1527,6 +1529,8 @@ protected:
   bool                      mSuppressInterruptibleReflows : 1;
   bool                      mScrollPositionClampingScrollPortSizeSet : 1;
 
+  uint32_t                  mPresShellId;
+
   // List of subtrees rooted at style scope roots that need to be restyled.
   // When a change to a scoped style sheet is made, we add the style scope
   // root to this array rather than setting mStylesHaveChanged = true, since

layout/base/nsPresShell.cpp

@@ -687,6 +687,7 @@ nsIPresShell::FrameSelection()
 //----------------------------------------------------------------------
 
 static bool sSynthMouseMove = true;
+static uint32_t sNextPresShellId;
 
 PresShell::PresShell()
   : mMouseLocation(NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE)
@@ -713,6 +714,7 @@ PresShell::PresShell()
 #else
   mIsFirstPaint = true;
 #endif
+  mPresShellId = sNextPresShellId++;
   mFrozen = false;
 #ifdef DEBUG
   mPresArenaAllocCount = 0;