Turn off computation of the interest rect in cc in synchronized paint mode.

third_party/WebKit/Source/platform/graphics/ContentLayerDelegate.cpp

Index: third_party/WebKit/Source/platform/graphics/ContentLayerDelegate.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/ContentLayerDelegate.cpp b/third_party/WebKit/Source/platform/graphics/ContentLayerDelegate.cpp
index cbf0c830bacec21ad6b48843a1003340ee00b807..44e11529153e6312987393130d259386c2bb3511 100644
--- a/third_party/WebKit/Source/platform/graphics/ContentLayerDelegate.cpp
+++ b/third_party/WebKit/Source/platform/graphics/ContentLayerDelegate.cpp
@@ -41,6 +41,7 @@
 #include "public/platform/WebRect.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkPicture.h"
+#include "ui/gfx/geometry/rect.h"
 
 namespace blink {
 
@@ -53,26 +54,26 @@ ContentLayerDelegate::~ContentLayerDelegate()
 {
 }
 
-PassRefPtr<TracedValue> toTracedValue(const WebRect& clip)
+PassRefPtr<TracedValue> toTracedValue(const gfx::Rect& recordingViewport)
 {
     RefPtr<TracedValue> tracedValue = TracedValue::create();
     tracedValue->beginArray("clip_rect");
-    tracedValue->pushInteger(clip.x);
-    tracedValue->pushInteger(clip.y);
-    tracedValue->pushInteger(clip.width);
-    tracedValue->pushInteger(clip.height);
+    tracedValue->pushInteger(recordingViewport.x());
+    tracedValue->pushInteger(recordingViewport.y());
+    tracedValue->pushInteger(recordingViewport.width());
+    tracedValue->pushInteger(recordingViewport.height());
     tracedValue->endArray();
     return tracedValue;
 }
 
-static void paintArtifactToWebDisplayItemList(WebDisplayItemList* list, const PaintArtifact& artifact, const WebRect& bounds)
+static void paintArtifactToWebDisplayItemList(WebDisplayItemList* list, const PaintArtifact& artifact, const gfx::Rect& recordingViewport)
 {
     if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
         // This is a temporary path to paint the artifact using the paint chunk
         // properties. Ultimately, we should instead split the artifact into
         // separate layers and send those to the compositor, instead of sending
         // one big flat SkPicture.
-        SkRect skBounds = SkRect::MakeXYWH(bounds.x, bounds.y, bounds.width, bounds.height);
+        SkRect skBounds = SkRect::MakeXYWH(recordingViewport.x(), recordingViewport.y(), recordingViewport.width(), recordingViewport.height());
         RefPtr<SkPicture> picture = paintArtifactToSkPicture(artifact, skBounds);
         // TODO(wkorman): Pass actual visual rect with the drawing item.
         list->appendDrawingItem(IntRect(), picture.get());
@@ -82,16 +83,18 @@ static void paintArtifactToWebDisplayItemList(WebDisplayItemList* list, const Pa
 }
 
 void ContentLayerDelegate::paintContents(
-    WebDisplayItemList* webDisplayItemList, const WebRect& clip,
+    WebDisplayItemList* webDisplayItemList, gfx::Rect* recordingViewport,
     WebContentLayerClient::PaintingControlSetting paintingControl)
 {
-    TRACE_EVENT1("blink,benchmark", "ContentLayerDelegate::paintContents", "clip_rect", toTracedValue(clip));
+    TRACE_EVENT1("blink,benchmark", "ContentLayerDelegate::paintContents", "clip_rect", toTracedValue(*recordingViewport));
 
     // TODO(pdr): Remove when slimming paint v2 is further along. This is only
     // here so the browser is usable during development and does not crash due
     // to committing the new display items twice.
     if (RuntimeEnabledFeatures::slimmingPaintSynchronizedPaintingEnabled()) {
-        paintArtifactToWebDisplayItemList(webDisplayItemList, m_painter->paintController()->paintArtifact(), clip);
+        IntRect interestRect = m_painter->interestRect();
+        *recordingViewport = gfx::Rect(interestRect.x(), interestRect.y(), interestRect.width(), interestRect.y());
+        paintArtifactToWebDisplayItemList(webDisplayItemList, m_painter->paintController()->paintArtifact(), *recordingViewport);
         return;
     }
 
@@ -111,11 +114,11 @@ void ContentLayerDelegate::paintContents(
         disabledMode = GraphicsContext::FullyDisabled;
     GraphicsContext context(*paintController, disabledMode);
 
-    IntRect interestRect = clip;
+    IntRect interestRect(recordingViewport->x(), recordingViewport->y(), recordingViewport->width(), recordingViewport->height());
     m_painter->paint(context, &interestRect);
 
     paintController->commitNewDisplayItems();
-    paintArtifactToWebDisplayItemList(webDisplayItemList, paintController->paintArtifact(), clip);
+    paintArtifactToWebDisplayItemList(webDisplayItemList, paintController->paintArtifact(), *recordingViewport);
 }
 
 size_t ContentLayerDelegate::approximateUnsharedMemoryUsage() const