Fix gradient background invalidation when HTML size changes

third_party/WebKit/Source/core/layout/LayoutView.cpp

Index: third_party/WebKit/Source/core/layout/LayoutView.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutView.cpp b/third_party/WebKit/Source/core/layout/LayoutView.cpp
index 0d20215151e181a1556d3fb4d8077c07015bc09f..cfaadacd7e9b7416b1e296619e9b3d9fc646b260 100644
--- a/third_party/WebKit/Source/core/layout/LayoutView.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutView.cpp
@@ -21,6 +21,7 @@
 
 #include "core/layout/LayoutView.h"
 
+#include <inttypes.h>
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/editing/FrameSelection.h"
@@ -38,6 +39,7 @@
 #include "core/layout/compositing/PaintLayerCompositor.h"
 #include "core/page/Page.h"
 #include "core/paint/PaintLayer.h"
+#include "core/paint/ViewPaintInvalidator.h"
 #include "core/paint/ViewPainter.h"
 #include "core/svg/SVGDocumentExtensions.h"
 #include "platform/Histogram.h"
@@ -48,7 +50,6 @@
 #include "platform/instrumentation/tracing/TracedValue.h"
 #include "public/platform/Platform.h"
 #include "wtf/PtrUtil.h"
-#include <inttypes.h>
 
 namespace blink {
 
@@ -226,6 +227,8 @@ void LayoutView::layout() {
   if (!document().paginated())
     setPageLogicalHeight(LayoutUnit());
 
+  // TODO(wangxianzhu): Move this into ViewPaintInvalidator when
+  // rootLayerScrolling is permanently enabled.
   IncludeScrollbarsInRect includeScrollbars =
       RuntimeEnabledFeatures::rootLayerScrollingEnabled() ? IncludeScrollbars
                                                           : ExcludeScrollbars;
@@ -247,8 +250,6 @@ void LayoutView::layout() {
 
   SubtreeLayoutScope layoutScope(*this);
 
-  LayoutRect oldLayoutOverflowRect = layoutOverflowRect();
-
   // Use calcWidth/Height to get the new width/height, since this will take the
   // full page zoom factor into account.
   bool relayoutChildren =
@@ -283,17 +284,6 @@ void LayoutView::layout() {
 
   layoutContent();
 
-  if (layoutOverflowRect() != oldLayoutOverflowRect) {
-    // The document element paints the viewport background, so we need to
-    // invalidate it when layout overflow changes.
-    // FIXME: Improve viewport background styling/invalidation/painting.
-    // crbug.com/475115
-    if (Element* documentElement = document().documentElement()) {
-      if (LayoutObject* rootObject = documentElement->layoutObject())
-        rootObject->setShouldDoFullPaintInvalidation();
-    }
-  }
-
 #if DCHECK_IS_ON()
   checkLayoutState();
 #endif
@@ -425,6 +415,16 @@ void LayoutView::computeSelfHitTestRects(Vector<LayoutRect>& rects,
       LayoutRect(LayoutPoint::zero(), LayoutSize(frameView()->contentsSize())));
 }
 
+PaintInvalidationReason LayoutView::invalidatePaintIfNeeded(
+    const PaintInvalidationState& paintInvalidationState) {
+  return LayoutBlockFlow::invalidatePaintIfNeeded(paintInvalidationState);
+}
+
+PaintInvalidationReason LayoutView::invalidatePaintIfNeeded(
+    const PaintInvalidatorContext& context) const {
+  return ViewPaintInvalidator(*this, context).invalidatePaintIfNeeded();
+}
+
 void LayoutView::paint(const PaintInfo& paintInfo,
                        const LayoutPoint& paintOffset) const {
   ViewPainter(*this).paint(paintInfo, paintOffset);