Bug 1824480 - Remove ScrollMetadata::mBackgroundColor which is no longer used. r=dlrobertson

This field appears to be unused since bug 1349418.

Differential Revision: https://phabricator.services.mozilla.com/D173598

gfx/layers/FrameMetrics.cpp

@@ -323,8 +323,7 @@ std::ostream& operator<<(std::ostream& aStream,
 std::ostream& operator<<(std::ostream& aStream,
                          const ScrollMetadata& aMetadata) {
   aStream << "{ [description=" << aMetadata.GetContentDescription()
-          << "] [metrics=" << aMetadata.GetMetrics()
-          << "] [color=" << aMetadata.GetBackgroundColor();
+          << "] [metrics=" << aMetadata.GetMetrics();
   if (aMetadata.GetScrollParentId() != ScrollableLayerGuid::NULL_SCROLL_ID) {
     aStream << "] [scrollParent=" << aMetadata.GetScrollParentId();
   }
@@ -337,11 +336,6 @@ std::ostream& operator<<(std::ostream& aStream,
   return aStream;
 }
 
-void ScrollMetadata::SetBackgroundColor(
-    const gfx::sRGBColor& aBackgroundColor) {
-  mBackgroundColor = gfx::ToDeviceColor(aBackgroundColor);
-}
-
 StaticAutoPtr<const ScrollMetadata> ScrollMetadata::sNullMetadata;
 
 }  // namespace layers

gfx/layers/FrameMetrics.h

@@ -849,7 +849,6 @@ struct ScrollMetadata {
       : mMetrics(),
         mSnapInfo(),
         mScrollParentId(ScrollableLayerGuid::NULL_SCROLL_ID),
-        mBackgroundColor(),
         mContentDescription(),
         mLineScrollAmount(0, 0),
         mPageScrollAmount(0, 0),
@@ -868,7 +867,6 @@ struct ScrollMetadata {
   bool operator==(const ScrollMetadata& aOther) const {
     return mMetrics == aOther.mMetrics && mSnapInfo == aOther.mSnapInfo &&
            mScrollParentId == aOther.mScrollParentId &&
-           mBackgroundColor == aOther.mBackgroundColor &&
            // don't compare mContentDescription
            mLineScrollAmount == aOther.mLineScrollAmount &&
            mPageScrollAmount == aOther.mPageScrollAmount &&
@@ -910,10 +908,6 @@ struct ScrollMetadata {
   ViewID GetScrollParentId() const { return mScrollParentId; }
 
   void SetScrollParentId(ViewID aParentId) { mScrollParentId = aParentId; }
-  const gfx::DeviceColor& GetBackgroundColor() const {
-    return mBackgroundColor;
-  }
-  void SetBackgroundColor(const gfx::sRGBColor& aBackgroundColor);
   const nsCString& GetContentDescription() const { return mContentDescription; }
   void SetContentDescription(const nsCString& aContentDescription) {
     mContentDescription = aContentDescription;
@@ -1022,9 +1016,6 @@ struct ScrollMetadata {
   // off.
   ViewID mScrollParentId;
 
-  // The background color to use when overscrolling.
-  gfx::DeviceColor mBackgroundColor;
-
   // A description of the content element corresponding to this frame.
   // This is empty unless this is a scrollable layer and the
   // apz.printtree pref is turned on.

gfx/layers/ipc/LayersMessageUtils.h

@@ -558,7 +558,6 @@ struct ParamTraits<mozilla::layers::ScrollMetadata>
     WriteParam(aWriter, aParam.mMetrics);
     WriteParam(aWriter, aParam.mSnapInfo);
     WriteParam(aWriter, aParam.mScrollParentId);
-    WriteParam(aWriter, aParam.mBackgroundColor);
     WriteParam(aWriter, aParam.GetContentDescription());
     WriteParam(aWriter, aParam.mLineScrollAmount);
     WriteParam(aWriter, aParam.mPageScrollAmount);
@@ -591,7 +590,6 @@ struct ParamTraits<mozilla::layers::ScrollMetadata>
     return (ReadParam(aReader, &aResult->mMetrics) &&
             ReadParam(aReader, &aResult->mSnapInfo) &&
             ReadParam(aReader, &aResult->mScrollParentId) &&
-            ReadParam(aReader, &aResult->mBackgroundColor) &&
             ReadContentDescription(aReader, aResult) &&
             ReadParam(aReader, &aResult->mLineScrollAmount) &&
             ReadParam(aReader, &aResult->mPageScrollAmount) &&

layout/base/nsLayoutUtils.cpp

@@ -8982,20 +8982,6 @@ ScrollMetadata nsLayoutUtils::ComputeScrollMetadata(
     metadata.SetHasScrollgrab(true);
   }
 
-  // Also compute and set the background color.
-  // This is needed for APZ overscrolling support.
-  if (aScrollFrame) {
-    if (isRootScrollFrame) {
-      metadata.SetBackgroundColor(
-          sRGBColor::FromABGR(presShell->GetCanvasBackground()));
-    } else if (const auto* backgroundStyle =
-                   nsCSSRendering::FindBackground(aScrollFrame)) {
-      nscolor backgroundColor =
-          backgroundStyle->StyleBackground()->BackgroundColor(backgroundStyle);
-      metadata.SetBackgroundColor(sRGBColor::FromABGR(backgroundColor));
-    }
-  }
-
   if (ShouldDisableApzForElement(aContent)) {
     metadata.SetForceDisableApz(true);
   }