Allow ContainerLayers to track their invalid regions. (bug 1365879 part 16, r=mattwoodrow)

gfx/layers/LayerTreeInvalidation.cpp

@@ -123,7 +123,7 @@ NotifySubdocumentInvalidation(Layer* aLayer, NotifySubDocInvalidationFunc aCallb
       aLayer,
       [aCallback] (Layer* layer)
       {
-        layer->ClearInvalidRect();
+        layer->ClearInvalidRegion();
         if (layer->GetMaskLayer()) {
           NotifySubdocumentInvalidation(layer->GetMaskLayer(), aCallback);
         }
@@ -252,7 +252,7 @@ public:
       }
     }
 
-    mLayer->ClearInvalidRect();
+    mLayer->ClearInvalidRegion();
     return result;
   }
 
@@ -322,12 +322,13 @@ public:
     container->CheckCanary();
 
     bool childrenChanged = false;
-
+    bool invalidateWholeLayer = false;
     if (mPreXScale != container->GetPreXScale() ||
         mPreYScale != container->GetPreYScale()) {
       invalidOfLayer = OldTransformedBounds();
       AddRegion(invalidOfLayer, NewTransformedBounds());
       childrenChanged = true;
+      invalidateWholeLayer = true;
 
       // Can't bail out early, we need to update the child container layers
     }
@@ -419,6 +420,13 @@ public:
       container->SetChildrenChanged(true);
     }
 
+    if (container->UseIntermediateSurface()) {
+      IntRect bounds = invalidateWholeLayer
+                       ? mLayer->GetLocalVisibleRegion().ToUnknownRegion().GetBounds()
+                       : result.GetBounds();
+      container->SetInvalidCompositeRect(bounds);
+    }
+
     if (!mLayer->Extend3DContext()) {
       // |result| contains invalid regions only of children.
       result.Transform(GetTransformForInvalidation(mLayer));
@@ -427,7 +435,6 @@ public:
 
     LTI_DUMP(invalidOfLayer, "invalidOfLayer");
     result.OrWith(invalidOfLayer);
-
     return result;
   }
 
@@ -739,7 +746,7 @@ LayerProperties::ClearInvalidations(Layer *aLayer)
         aLayer,
         [] (Layer* layer)
         {
-          layer->ClearInvalidRect();
+          layer->ClearInvalidRegion();
           if (layer->GetMaskLayer()) {
             ClearInvalidations(layer->GetMaskLayer());
           }

gfx/layers/Layers.h

@@ -1806,7 +1806,7 @@ public:
    * Clear the invalid rect, marking the layer as being identical to what is currently
    * composited.
    */
-  virtual void ClearInvalidRect() { mInvalidRegion.SetEmpty(); }
+  virtual void ClearInvalidRegion() { mInvalidRegion.SetEmpty(); }
 
   // These functions allow attaching an AsyncPanZoomController to this layer,
   // and can be used anytime.
@@ -2044,7 +2044,7 @@ public:
     mValidRegionIsCurrent = false;
   }
 
-  void ClearInvalidRect() override
+  void ClearInvalidRegion() override
   {
     // mInvalidRegion is about to be reset. This is the last chance to apply
     // any pending changes from it to mValidRegion. Do that by calling
@@ -2335,6 +2335,8 @@ public:
   }
 
   nsTArray<CSSFilter>& GetFilterChain() { return mFilterChain; }
+  
+  virtual void SetInvalidCompositeRect(const gfx::IntRect& aRect) {}
 
 protected:
   friend class ReadbackProcessor;