Bug 1504924 - Avoid nsIFrame::IsSelected() call in nsDisplayText::CanApplyOpacity() r=mats

Differential Revision: https://phabricator.services.mozilla.com/D12750

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

layout/generic/nsTextFrame.cpp

@@ -4986,11 +4986,11 @@ public:
 
   bool CanApplyOpacity() const final
   {
-    nsTextFrame* f = static_cast<nsTextFrame*>(mFrame);
+    if (IsSelected()) {
-    if (f->IsSelected()) {
       return false;
     }
 
+    nsTextFrame* f = static_cast<nsTextFrame*>(mFrame);
     const nsStyleText* textStyle = f->StyleText();
     if (textStyle->mTextShadow) {
       return false;
@@ -6983,12 +6983,12 @@ nsTextFrame::PaintText(const PaintTextParams& aParams,
     return;
 
   PropertyProvider provider(this, iter, nsTextFrame::eInflated);
-  if (aItem.mIsFrameSelected.isNothing()) {
+
-    aItem.mIsFrameSelected.emplace(IsSelected());
+  const bool isSelected = aItem.IsSelected();
-  }
+
   // Trim trailing whitespace, unless we're painting a selection highlight,
   // which should include trailing spaces if present (bug 1146754).
-  provider.InitializeForDisplay(!aItem.mIsFrameSelected.value());
+  provider.InitializeForDisplay(!isSelected);
 
   const bool reversed = mTextRun->IsInlineReversed();
   const bool verticalRun = mTextRun->IsVertical();
@@ -7032,7 +7032,7 @@ nsTextFrame::PaintText(const PaintTextParams& aParams,
   textPaintStyle.SetResolveColors(!aParams.callbacks);
 
   // Fork off to the (slower) paint-with-selection path if necessary.
-  if (aItem.mIsFrameSelected.value() &&
+  if (isSelected &&
       (aParams.IsPaintBGColor() || ShouldDrawSelection(this->GetParent()))) {
     MOZ_ASSERT(aOpacity == 1.0f, "We don't support opacity with selections!");
     gfxSkipCharsIterator tmp(provider.GetStart());

layout/painting/nsDisplayList.h

@@ -7767,6 +7767,15 @@ public:
              : nullptr;
   }
 
+  bool IsSelected() const
+  {
+    if (mIsFrameSelected.isNothing()) {
+      mIsFrameSelected.emplace(mFrame->IsSelected());
+    }
+
+    return mIsFrameSelected.value();
+  }
+
   // Lengths measured from the visual inline start and end sides
   // (i.e. left and right respectively in horizontal writing modes,
   // regardless of bidi directionality; top and bottom in vertical modes).