From 7cdfa1649e821fff80db5da2b12f886b82f6364d Mon Sep 17 00:00:00 2001
From: Mats Palmgren <mats@mozilla.com>
Date: Thu, 29 Nov 2018 00:17:25 +0100
Subject: [PATCH] Bug 1509903 part 1 - Make nsTextFrame::IsFrameSelected()
 'final' and inline nsIFrame::IsSelected() to de-virtualize the
 IsFrameSelected() call in some cases.  r=emilio

In particular, in nsCharClipDisplayItem::IsSelected() we know that
the frame must be a nsTextFrame (or nsContinuingTextFrame) which
means nsTextFrame::IsFrameSelected() can be called directly now.
---
 layout/generic/nsFrame.cpp        |  7 -------
 layout/generic/nsIFrame.h         |  5 ++++-
 layout/generic/nsTextFrame.h      |  2 +-
 layout/painting/nsDisplayList.cpp | 13 +++++++++++++
 layout/painting/nsDisplayList.h   |  9 +--------
 5 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/layout/generic/nsFrame.cpp b/layout/generic/nsFrame.cpp
index fbc143fe4050..add3e263ce00 100644
--- a/layout/generic/nsFrame.cpp
+++ b/layout/generic/nsFrame.cpp
@@ -11030,13 +11030,6 @@ nsIFrame::CreateOwnLayerIfNeeded(nsDisplayListBuilder* aBuilder,
   }
 }
 
-bool
-nsIFrame::IsSelected() const
-{
-  return (GetContent() && GetContent()->IsSelectionDescendant()) ?
-    IsFrameSelected() : false;
-}
-
 bool
 nsIFrame::IsStackingContext(EffectSet* aEffectSet,
                             const nsStyleDisplay* aStyleDisplay,
diff --git a/layout/generic/nsIFrame.h b/layout/generic/nsIFrame.h
index edc0822a5249..c11ae9741762 100644
--- a/layout/generic/nsIFrame.h
+++ b/layout/generic/nsIFrame.h
@@ -3232,7 +3232,10 @@ public:
   /**
    * @returns true if this frame is selected.
    */
-  bool IsSelected() const;
+  bool IsSelected() const {
+    return (GetContent() && GetContent()->IsSelectionDescendant()) ?
+      IsFrameSelected() : false;
+  }
 
   /**
    *  called to discover where this frame, or a parent frame has user-select style
diff --git a/layout/generic/nsTextFrame.h b/layout/generic/nsTextFrame.h
index 4f61cfac067e..e59850ea3e55 100644
--- a/layout/generic/nsTextFrame.h
+++ b/layout/generic/nsTextFrame.h
@@ -704,7 +704,7 @@ protected:
    * Return true if the frame is part of a Selection.
    * Helper method to implement the public IsSelected() API.
    */
-  bool IsFrameSelected() const override;
+  bool IsFrameSelected() const final;
 
   mozilla::UniquePtr<SelectionDetails> GetSelectionDetails();
 
diff --git a/layout/painting/nsDisplayList.cpp b/layout/painting/nsDisplayList.cpp
index cdcd5f28e4d3..e7c762b06ec1 100644
--- a/layout/painting/nsDisplayList.cpp
+++ b/layout/painting/nsDisplayList.cpp
@@ -90,6 +90,7 @@
 #include "nsSVGMaskFrame.h"
 #include "nsTableCellFrame.h"
 #include "nsTableColFrame.h"
+#include "nsTextFrame.h"
 #include "nsSliderFrame.h"
 #include "ClientLayerManager.h"
 #include "mozilla/layers/StackingContextHelper.h"
@@ -9604,6 +9605,18 @@ nsCharClipDisplayItem::ComputeInvalidationRegion(
   }
 }
 
+bool
+nsCharClipDisplayItem::IsSelected() const
+{
+  if (mIsFrameSelected.isNothing()) {
+    MOZ_ASSERT((nsTextFrame*)do_QueryFrame(mFrame));
+    auto* f = static_cast<nsTextFrame*>(mFrame);
+    mIsFrameSelected.emplace(f->IsSelected());
+  }
+
+  return mIsFrameSelected.value();
+}
+
 nsDisplayEffectsBase::nsDisplayEffectsBase(
   nsDisplayListBuilder* aBuilder,
   nsIFrame* aFrame,
diff --git a/layout/painting/nsDisplayList.h b/layout/painting/nsDisplayList.h
index d47c52c518bf..0399a43f90a3 100644
--- a/layout/painting/nsDisplayList.h
+++ b/layout/painting/nsDisplayList.h
@@ -7798,14 +7798,7 @@ public:
              : nullptr;
   }
 
-  bool IsSelected() const
-  {
-    if (mIsFrameSelected.isNothing()) {
-      mIsFrameSelected.emplace(mFrame->IsSelected());
-    }
-
-    return mIsFrameSelected.value();
-  }
+  bool IsSelected() const;
 
   // Lengths measured from the visual inline start and end sides
   // (i.e. left and right respectively in horizontal writing modes,