Let synchronized painting generate correct paint invalidation rects

third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp

Index: third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp b/third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp
index e6c10a9539fe3bb8b396b26f212a0bcb1c8449f6..2d0ae56f58211ee11e2242067438d118d8f964c1 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp
+++ b/third_party/WebKit/Source/platform/graphics/paint/PaintController.cpp
@@ -112,18 +112,16 @@ void PaintController::endScope()
     endSkippingCache();
 }
 
-void PaintController::invalidate(const DisplayItemClientWrapper& client, PaintInvalidationReason paintInvalidationReason, const IntRect& previousPaintInvalidationRect, const IntRect& newPaintInvalidationRect)
+void PaintController::invalidate(const DisplayItemClientWrapper& client, PaintInvalidationReason paintInvalidationReason, const Vector<IntRect>& paintInvalidationRects)
 {
     invalidateClient(client);
 
-    if (RuntimeEnabledFeatures::slimmingPaintSynchronizedPaintingEnabled()) {
-        Invalidation invalidation = { previousPaintInvalidationRect, paintInvalidationReason };
-        if (!previousPaintInvalidationRect.isEmpty())
-            m_invalidations.append(invalidation);
-        if (newPaintInvalidationRect != previousPaintInvalidationRect && !newPaintInvalidationRect.isEmpty()) {
-            invalidation.rect = newPaintInvalidationRect;
-            m_invalidations.append(invalidation);
-        }
+    if (!RuntimeEnabledFeatures::slimmingPaintSynchronizedPaintingEnabled())
+        return;
+
+    for (auto& rect : paintInvalidationRects) {
+        Invalidation invalidation = { rect, paintInvalidationReason };
+        m_invalidations.append(invalidation);
     }
 }