Bug 967844. Part 1: Move mBackgroundColor from Layer to FrameMetrics. r=kats

--HG--
extra : rebase_source : b5fd1fd1b0b1f55990e72d205cc871a46d5f4f8c

gfx/ipc/GfxMessageUtils.h

@@ -753,6 +753,7 @@ struct ParamTraits<mozilla::layers::FrameMetrics>
     WriteParam(aMsg, aParam.mUpdateScrollOffset);
     WriteParam(aMsg, aParam.mScrollGeneration);
     WriteParam(aMsg, aParam.mTransformScale);
+    WriteParam(aMsg, aParam.mBackgroundColor);
   }
 
   static bool Read(const Message* aMsg, void** aIter, paramType* aResult)
@@ -779,7 +780,8 @@ struct ParamTraits<mozilla::layers::FrameMetrics>
             ReadParam(aMsg, aIter, &aResult->mHasScrollgrab) &&
             ReadParam(aMsg, aIter, &aResult->mUpdateScrollOffset) &&
             ReadParam(aMsg, aIter, &aResult->mScrollGeneration) &&
-            ReadParam(aMsg, aIter, &aResult->mTransformScale));
+            ReadParam(aMsg, aIter, &aResult->mTransformScale) &&
+            ReadParam(aMsg, aIter, &aResult->mBackgroundColor));
   }
 };
 

gfx/layers/FrameMetrics.h

@@ -12,6 +12,7 @@
 #include "mozilla/gfx/Rect.h"           // for RoundedIn
 #include "mozilla/gfx/ScaleFactor.h"    // for ScaleFactor
 #include "mozilla/gfx/Logging.h"        // for Log
+#include "gfxColor.h"
 
 namespace IPC {
 template <typename T> struct ParamTraits;
@@ -97,6 +98,7 @@ public:
     , mUseDisplayPortMargins(false)
     , mPresShellId(-1)
     , mViewport(0, 0, 0, 0)
+    , mBackgroundColor(0, 0, 0, 0)
   {}
 
   // Default copy ctor and operator= are fine
@@ -122,7 +124,8 @@ public:
            mScrollParentId == aOther.mScrollParentId &&
            mScrollOffset == aOther.mScrollOffset &&
            mHasScrollgrab == aOther.mHasScrollgrab &&
-           mUpdateScrollOffset == aOther.mUpdateScrollOffset;
+           mUpdateScrollOffset == aOther.mUpdateScrollOffset &&
+           mBackgroundColor == aOther.mBackgroundColor;
   }
   bool operator!=(const FrameMetrics& aOther) const
   {
@@ -467,6 +470,16 @@ public:
     return mViewport;
   }
 
+  const gfxRGBA& GetBackgroundColor() const
+  {
+    return mBackgroundColor;
+  }
+
+  void SetBackgroundColor(const gfxRGBA& aBackgroundColor)
+  {
+    mBackgroundColor = aBackgroundColor;
+  }
+
 private:
   // New fields from now on should be made private and old fields should
   // be refactored to be private.
@@ -535,6 +548,9 @@ private:
   // iframe. For layers that don't correspond to a document, this metric is
   // meaningless and invalid.
   CSSRect mViewport;
+
+  // The background color to use when overscrolling.
+  gfxRGBA mBackgroundColor;
 };
 
 /**

gfx/layers/Layers.cpp

@@ -209,8 +209,7 @@ Layer::Layer(LayerManager* aManager, void* aImplData) :
   mScrollbarTargetId(FrameMetrics::NULL_SCROLL_ID),
   mScrollbarDirection(ScrollDirection::NONE),
   mDebugColorIndex(0),
-  mAnimationGeneration(0),
-  mBackgroundColor(0, 0, 0, 0)
+  mAnimationGeneration(0)
 {}
 
 Layer::~Layer()

gfx/layers/Layers.h

@@ -1171,17 +1171,6 @@ public:
     }
   }
 
-  void SetBackgroundColor(const gfxRGBA& aColor)
-  {
-    if (mBackgroundColor == aColor) {
-      return;
-    }
-
-    MOZ_LAYERS_LOG_IF_SHADOWABLE(this, ("Layer::Mutated(%p) BackgroundColor", this));
-    mBackgroundColor = aColor;
-    Mutated();
-  }
-
   void SetContentDescription(const std::string& aContentDescription)
   {
     if (mContentDescription == aContentDescription) {
@@ -1226,7 +1215,6 @@ public:
   FrameMetrics::ViewID GetScrollbarTargetContainerId() { return mScrollbarTargetId; }
   ScrollDirection GetScrollbarDirection() { return mScrollbarDirection; }
   Layer* GetMaskLayer() const { return mMaskLayer; }
-  gfxRGBA GetBackgroundColor() const { return mBackgroundColor; }
   const std::string& GetContentDescription() const { return mContentDescription; }
 
 
@@ -1655,8 +1643,6 @@ protected:
   // If this layer is used for OMTA, then this counter is used to ensure we
   // stay in sync with the animation manager
   uint64_t mAnimationGeneration;
-  // This is currently set and used only for scrollable container layers.
-  gfxRGBA mBackgroundColor;
   // A description of the content element corresponding to this frame.
   // This is empty unless this is a scrollable ContainerLayer and the
   // apz.printtree pref is turned on.

gfx/layers/composite/ContainerLayerComposite.cpp

@@ -268,15 +268,16 @@ RenderLayers(ContainerT* aContainer,
   // placeholder for APZ purposes.
   if (aContainer->HasScrollableFrameMetrics() && !aContainer->IsScrollInfoLayer()) {
     bool overscrolled = false;
+    gfxRGBA color;
     for (uint32_t i = 0; i < aContainer->GetFrameMetricsCount(); i++) {
       AsyncPanZoomController* apzc = aContainer->GetAsyncPanZoomController(i);
       if (apzc && apzc->IsOverscrolled()) {
         overscrolled = true;
+        color = aContainer->GetFrameMetrics(i).GetBackgroundColor();
         break;
       }
     }
     if (overscrolled) {
-      gfxRGBA color = aContainer->GetBackgroundColor();
       // If the background is completely transparent, there's no point in
       // drawing anything for it. Hopefully the layers behind, if any, will
       // provide suitable content for the overscroll effect.

gfx/layers/composite/TiledContentHost.cpp

@@ -367,9 +367,9 @@ TiledContentHost::Composite(EffectChain& aEffectChain,
   if (aOpacity == 1.0f && gfxPrefs::LowPrecisionOpacity() < 1.0f) {
     // Background colors are only stored on scrollable layers. Grab
     // the one from the nearest scrollable ancestor layer.
-    for (Layer* ancestor = GetLayer(); ancestor; ancestor = ancestor->GetParent()) {
-      if (ancestor->HasScrollableFrameMetrics()) {
-        backgroundColor = ancestor->GetBackgroundColor();
+    for (LayerMetricsWrapper ancestor(GetLayer(), LayerMetricsWrapper::StartAt::BOTTOM); ancestor; ancestor = ancestor.GetParent()) {
+      if (ancestor.Metrics().IsScrollable()) {
+        backgroundColor = ancestor.Metrics().GetBackgroundColor();
         break;
       }
     }

gfx/layers/ipc/LayerTransactionParent.cpp

@@ -321,7 +321,6 @@ LayerTransactionParent::RecvUpdate(const InfallibleTArray<Edit>& cset,
       layer->SetAnimations(common.animations());
       layer->SetInvalidRegion(common.invalidRegion());
       layer->SetFrameMetrics(common.metrics());
-      layer->SetBackgroundColor(common.backgroundColor().value());
       layer->SetContentDescription(common.contentDescription());
 
       typedef SpecificLayerAttributes Specific;

gfx/layers/ipc/LayersMessages.ipdlh

@@ -216,7 +216,6 @@ struct CommonLayerAttributes {
   Animation[] animations;
   nsIntRegion invalidRegion;
   FrameMetrics[] metrics;
-  LayerColor backgroundColor;
   string contentDescription;
 };
 

gfx/layers/ipc/ShadowLayers.cpp

@@ -609,7 +609,6 @@ ShadowLayerForwarder::EndTransaction(InfallibleTArray<EditReply>* aReplies,
     common.animations() = mutant->GetAnimations();
     common.invalidRegion() = mutant->GetInvalidRegion();
     common.metrics() = mutant->GetAllFrameMetrics();
-    common.backgroundColor() = mutant->GetBackgroundColor();
     common.contentDescription() = mutant->GetContentDescription();
     attrs.specific() = null_t();
     mutant->FillSpecificAttributes(attrs.specific());

layout/base/nsDisplayList.cpp

@@ -848,20 +848,20 @@ static void RecordFrameMetrics(nsIFrame* aForFrame,
     metrics.SetHasScrollgrab(true);
   }
 
-  aRoot->SetFrameMetrics(metrics);
-
-  // Also compute and set the background color on the container.
+  // Also compute and set the background color.
   // This is needed for APZ overscrolling support.
   if (aScrollFrame) {
     if (isRootScrollFrame) {
-      aRoot->SetBackgroundColor(presShell->GetCanvasBackground());
+      metrics.SetBackgroundColor(presShell->GetCanvasBackground());
     } else {
       nsStyleContext* backgroundStyle;
       if (nsCSSRendering::FindBackground(aScrollFrame, &backgroundStyle)) {
-        aRoot->SetBackgroundColor(backgroundStyle->StyleBackground()->mBackgroundColor);
+        metrics.SetBackgroundColor(backgroundStyle->StyleBackground()->mBackgroundColor);
       }
     }
   }
+
+  aRoot->SetFrameMetrics(metrics);
 }
 
 nsDisplayListBuilder::~nsDisplayListBuilder() {