Optimize layout/repaint on FrameView resize

Source/core/rendering/RenderView.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 115 matching lines @@
 #if !ASSERT_DISABLED
     bool layoutDeltaMatches(const LayoutSize& delta)
     {
         ASSERT(!RuntimeEnabledFeatures::repaintAfterLayoutEnabled());
         if (!m_layoutState)
             return false;
         return (delta.width() == m_layoutState->m_layoutDelta.width() || m_layoutState->m_layoutDeltaXSaturated) && (delta.height() == m_layoutState->m_layoutDelta.height() || m_layoutState->m_layoutDeltaYSaturated);
     }
 #endif
 
-    bool doingFullRepaint() const { return m_frameView->needsFullRepaint(); }
-
     // Subtree push
     void pushLayoutState(RenderObject&);
 
     void popLayoutState()
     {
         LayoutState* state = m_layoutState;
         m_layoutState = state->m_next;
         delete state;
         popLayoutStateForCurrentFlowThread();
     }
@@ skipping 63 matching lines @@
     virtual void mapAbsoluteToLocalPoint(MapCoordinatesFlags, TransformState&) const OVERRIDE;
     virtual void computeSelfHitTestRects(Vector<LayoutRect>&, const LayoutPoint& layerOffset) const OVERRIDE;
 
     void initializeLayoutState(LayoutState&);
 
     bool shouldRepaint(const LayoutRect&) const;
 
     bool rootFillsViewportBackground(RenderBox* rootBox) const;
 
     // These functions may only be accessed by LayoutStateMaintainer.
-    bool pushLayoutState(RenderBox& renderer, const LayoutSize& offset, LayoutUnit pageHeight = 0, bool pageHeightChanged = false, ColumnInfo* colInfo = 0)
+    void pushLayoutState(RenderBox& renderer, const LayoutSize& offset, LayoutUnit pageHeight = 0, bool pageHeightChanged = false, ColumnInfo* colInfo = 0)
     {
-        // We push LayoutState even if layoutState is disabled because it stores layoutDelta too.
-        if (!doingFullRepaint() || m_layoutState->isPaginated() || renderer.hasColumns() || renderer.flowThreadContainingBlock()
-            || (renderer.isRenderBlock() && toRenderBlock(renderer).shapeInsideInfo())
-            || (m_layoutState->shapeInsideInfo() && renderer.isRenderBlock() && !toRenderBlock(renderer).allowsShapeInsideInfoSharing(&m_layoutState->shapeInsideInfo()->owner()))
-            ) {
-            pushLayoutStateForCurrentFlowThread(renderer);
-            m_layoutState = new LayoutState(m_layoutState, renderer, offset, pageHeight, pageHeightChanged, colInfo);
-            return true;
-        }
-        return false;
+        pushLayoutStateForCurrentFlowThread(renderer);
+        m_layoutState = new LayoutState(m_layoutState, renderer, offset, pageHeight, pageHeightChanged, colInfo);
     }
 
     void layoutContent(const LayoutState&);
 #ifndef NDEBUG
     void checkLayoutState(const LayoutState&);
 #endif
 
     void positionDialog(RenderBox*);
     void positionDialogs();
 
@@ skipping 33 matching lines @@
 // Stack-based class to assist with LayoutState push/pop
 class LayoutStateMaintainer {
     WTF_MAKE_NONCOPYABLE(LayoutStateMaintainer);
 public:
     // ctor to push now
     explicit LayoutStateMaintainer(RenderBox& root, const LayoutSize& offset, LayoutUnit pageHeight = 0, bool pageHeightChanged = false, ColumnInfo* colInfo = 0)
         : m_view(*root.view())
         , m_disabled(root.shouldDisableLayoutState())
         , m_didStart(false)
         , m_didEnd(false)
-        , m_didCreateLayoutState(false)
     {
         push(root, offset, pageHeight, pageHeightChanged, colInfo);
     }
 
     // ctor to maybe push later
     explicit LayoutStateMaintainer(RenderBox& root)
         : m_view(*root.view())
         , m_disabled(false)
         , m_didStart(false)
         , m_didEnd(false)
-        , m_didCreateLayoutState(false)
     {
     }
 
     ~LayoutStateMaintainer()
     {
         ASSERT(m_didStart == m_didEnd);   // if this fires, it means that someone did a push(), but forgot to pop().
     }
 
     void push(RenderBox& root, const LayoutSize& offset, LayoutUnit pageHeight = 0, bool pageHeightChanged = false, ColumnInfo* colInfo = 0)
     {
         ASSERT(!m_didStart);
         // We push state even if disabled, because we still need to store layoutDelta
-        m_didCreateLayoutState = m_view.pushLayoutState(root, offset, pageHeight, pageHeightChanged, colInfo);
-        if (m_disabled && m_didCreateLayoutState)
+        m_view.pushLayoutState(root, offset, pageHeight, pageHeightChanged, colInfo);
+        if (m_disabled)
             m_view.disableLayoutState();
         m_didStart = true;
     }
 
     void pop()
     {
         if (m_didStart) {
             ASSERT(!m_didEnd);
-            if (m_didCreateLayoutState) {
-                m_view.popLayoutState();
-                if (m_disabled)
-                    m_view.enableLayoutState();
-            }
+            m_view.popLayoutState();
+            if (m_disabled)
+                m_view.enableLayoutState();
 
             m_didEnd = true;
         }
     }
 
     bool didPush() const { return m_didStart; }
 
 private:
     RenderView& m_view;
     bool m_disabled : 1;        // true if the offset and clip part of layoutState is disabled
     bool m_didStart : 1;        // true if we did a push or disable
     bool m_didEnd : 1;          // true if we popped or re-enabled
-    bool m_didCreateLayoutState : 1; // true if we actually made a layout state.
 };
 
 class LayoutStateDisabler {
     WTF_MAKE_NONCOPYABLE(LayoutStateDisabler);
 public:
     LayoutStateDisabler(const RenderBox& root)
         : m_view(*root.view())
     {
         m_view.disableLayoutState();
     }
 
     ~LayoutStateDisabler()
     {
         m_view.enableLayoutState();
     }
 private:
     RenderView& m_view;
 };
 
 } // namespace WebCore
 
 #endif // RenderView_h