Bug 1521644 - Add a layer property that indicates async zoom container layers. r=mattwoodrow

MozReview-Commit-ID: 6qkFXhRDFs

Differential Revision: https://phabricator.services.mozilla.com/D17174

--HG--
extra : moz-landing-system : lando

gfx/layers/LayerAttributes.h

@@ -179,6 +179,14 @@ class SimpleLayerAttributes final {
     return true;
   }
 
+  bool SetIsAsyncZoomContainer(const Maybe<FrameMetrics::ViewID>& aViewId) {
+    if (mIsAsyncZoomContainerForViewId == aViewId) {
+      return false;
+    }
+    mIsAsyncZoomContainerForViewId = aViewId;
+    return true;
+  }
+
   bool SetScrollbarData(const ScrollbarData& aScrollbarData) {
     if (mScrollbarData == aScrollbarData) {
       return false;
@@ -292,6 +300,10 @@ class SimpleLayerAttributes final {
 
   bool IsFixedPosition() const { return mIsFixedPosition; }
 
+  Maybe<FrameMetrics::ViewID> IsAsyncZoomContainer() const {
+    return mIsAsyncZoomContainerForViewId;
+  }
+
   const ScrollbarData& GetScrollbarData() const { return mScrollbarData; }
 
   gfx::CompositionOp GetMixBlendMode() const { return mMixBlendMode; }
@@ -341,6 +353,8 @@ class SimpleLayerAttributes final {
            mContentFlags == aOther.mContentFlags &&
            mOpacity == aOther.mOpacity &&
            mIsFixedPosition == aOther.mIsFixedPosition &&
+           mIsAsyncZoomContainerForViewId ==
+               aOther.mIsAsyncZoomContainerForViewId &&
            mScrollbarData == aOther.mScrollbarData &&
            mMixBlendMode == aOther.mMixBlendMode &&
            mForceIsolatedGroup == aOther.mForceIsolatedGroup;
@@ -355,6 +369,7 @@ class SimpleLayerAttributes final {
   uint32_t mContentFlags;
   float mOpacity;
   bool mIsFixedPosition;
+  Maybe<FrameMetrics::ViewID> mIsAsyncZoomContainerForViewId;
   ScrollbarData mScrollbarData;
   gfx::CompositionOp mMixBlendMode;
   bool mForceIsolatedGroup;

gfx/layers/Layers.cpp

@@ -1718,6 +1718,11 @@ void Layer::PrintInfo(std::stringstream& aStream, const char* aPrefix) {
   if (Is3DContextLeaf()) {
     aStream << " [is3DContextLeaf]";
   }
+  if (Maybe<FrameMetrics::ViewID> viewId = IsAsyncZoomContainer()) {
+    aStream << nsPrintfCString(" [asyncZoomContainer scrollId=%" PRIu64 "]",
+                               *viewId)
+                   .get();
+  }
   if (IsScrollbarContainer()) {
     aStream << " [scrollbar]";
   }

gfx/layers/Layers.h

@@ -1216,6 +1216,14 @@ class Layer {
     }
   }
 
+  void SetIsAsyncZoomContainer(const Maybe<FrameMetrics::ViewID>& aViewId) {
+    if (mSimpleAttrs.SetIsAsyncZoomContainer(aViewId)) {
+      MOZ_LAYERS_LOG_IF_SHADOWABLE(
+          this, ("Layer::Mutated(%p) IsAsyncZoomContainer", this));
+      MutatedSimple();
+    }
+  }
+
   /**
    * CONSTRUCTION PHASE ONLY
    * This flag is true when the transform on the layer is a perspective
@@ -1359,6 +1367,9 @@ class Layer {
   virtual float GetPostXScale() const { return mSimpleAttrs.GetPostXScale(); }
   virtual float GetPostYScale() const { return mSimpleAttrs.GetPostYScale(); }
   bool GetIsFixedPosition() { return mSimpleAttrs.IsFixedPosition(); }
+  Maybe<FrameMetrics::ViewID> IsAsyncZoomContainer() {
+    return mSimpleAttrs.IsAsyncZoomContainer();
+  }
   bool GetTransformIsPerspective() const {
     return mSimpleAttrs.GetTransformIsPerspective();
   }