Fixed clip resize for document.rootScroller with inertTopControls

third_party/WebKit/Source/core/paint/PaintLayer.h

Index: third_party/WebKit/Source/core/paint/PaintLayer.h
diff --git a/third_party/WebKit/Source/core/paint/PaintLayer.h b/third_party/WebKit/Source/core/paint/PaintLayer.h
index b8b098a2569199aa9d4e5562d34e8e4cddbb01da..d93adb4aa995aa8dc21bd5d8eb71695dbb1ebc60 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.h
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.h
@@ -934,6 +934,11 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
     m_previousPaintPhaseDescendantOutlinesWasEmpty = isEmpty;
   }
 
+  void setIsGlobalRootScroller(bool isGlobalRootScroller) {

[chrishtr, 2016/11/18 00:37:09]

Why set these here? Why not just change all call sites to query whether the
PaintLayer in question is the one mentioned by globalRootScrollerController()?
Not caching it here means it can't possibly get out of sync.

[bokan, 2016/11/18 22:30:35]

Yah, that's probably better. Fixed.

+    m_isGlobalRootScroller = isGlobalRootScroller;
+  }
+  bool isGlobalRootScroller() { return m_isGlobalRootScroller; }
+
   // Similar to above, but for PaintPhaseFloat.
   bool needsPaintPhaseFloat() const {
     return m_needsPaintPhaseFloat && !m_previousPaintPhaseFloatWasEmpty;
@@ -1174,6 +1179,8 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
   unsigned m_needsPaintPhaseDescendantBlockBackgrounds : 1;
   unsigned m_previousPaintPhaseDescendantBlockBackgroundsWasEmpty : 1;
 
+  unsigned m_isGlobalRootScroller : 1;
+
   // These bitfields are part of ancestor/descendant dependent compositing
   // inputs.
   unsigned m_hasDescendantWithClipPath : 1;