Expand the clip rect for cull rect verification.

Source/platform/graphics/paint/DrawingRecorder.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "platform/graphics/paint/DrawingRecorder.h"
 
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/GraphicsLayer.h"
@@ skipping 36 matching lines @@
     if (!m_canUseCachedDrawing)
         context.beginRecording(cullRect);
 #endif
 
 #if ENABLE(ASSERT)
     if (RuntimeEnabledFeatures::slimmingPaintStrictCullRectClippingEnabled() && !m_canUseCachedDrawing) {
         // Skia depends on the cull rect containing all of the display item commands. When strict
         // cull rect clipping is enabled, make this explicit. This allows us to identify potential
         // incorrect cull rects that might otherwise be masked due to Skia internal optimizations.
         context.save();
-        context.clipRect(enclosingIntRect(cullRect), NotAntiAliased, SkRegion::kIntersect_Op);
+        IntRect verificationClip = enclosingIntRect(cullRect);
+        // Expand the verification clip by one pixel to account for Skia's SkCanvas::getClipBounds()
+        // expansion, used in testing cull rects.
+        // TODO(schenney) This is not the best place to do this. Ideally, we would expand by one pixel
+        // in device (pixel) space, but to do that we would need to add the verification mode to Skia.
+        verificationClip.inflate(1);
+        context.clipRect(verificationClip, NotAntiAliased, SkRegion::kIntersect_Op);
     }
 #endif
 }
 
 DrawingRecorder::~DrawingRecorder()
 {
     if (!RuntimeEnabledFeatures::slimmingPaintEnabled())
         return;
 
     ASSERT(m_context.displayItemList());
@@ skipping 21 matching lines @@
     } else {
         OwnPtr<DrawingDisplayItem> drawingDisplayItem = DrawingDisplayItem::create(m_displayItemClient, m_displayItemType, m_context.endRecording());
 #if ENABLE(ASSERT)
         drawingDisplayItem->setUnderInvalidationCheckingMode(m_underInvalidationCheckingMode);
 #endif
         m_context.displayItemList()->add(drawingDisplayItem.release());
     }
 }
 
 } // namespace blink