Make OffscreenCanvas resizeable

third_party/WebKit/Source/modules/canvas2d/CanvasRenderingContext2D.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc.
  * All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012, 2013 Intel Corporation. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
@@ skipping 123 matching lines @@
   setShouldAntialias(true);
   ThreadState::current()->registerPreFinalizer(this);
   validateStateStack();
 }
 
 void CanvasRenderingContext2D::setCanvasGetContextResult(
     RenderingContext& result) {
   result.setCanvasRenderingContext2D(this);
 }
 
-void CanvasRenderingContext2D::unwindStateStack() {
-  if (size_t stackSize = m_stateStack.size()) {
-    if (SkCanvas* skCanvas = canvas()->existingDrawingCanvas()) {
-      while (--stackSize)
-        skCanvas->restore();
-    }
-  }
-}
-
 CanvasRenderingContext2D::~CanvasRenderingContext2D() {}
 
 void CanvasRenderingContext2D::dispose() {
   if (m_pruneLocalFontCacheScheduled)
     Platform::current()->currentThread()->removeTaskObserver(this);
 }
 
 void CanvasRenderingContext2D::validateStateStack() const {
 #if DCHECK_IS_ON()
   if (SkCanvas* skCanvas = canvas()->existingDrawingCanvas()) {
@@ skipping 110 matching lines @@
     return;
   reset();
   m_contextLostMode = NotLostContext;
   if (contextLostRestoredEventsEnabled()) {
     Event* event(Event::create(EventTypeNames::contextrestored));
     canvas()->dispatchEvent(event);
   }
 }
 
 void CanvasRenderingContext2D::reset() {
-  validateStateStack();
-  unwindStateStack();
-  m_stateStack.resize(1);
-  m_stateStack.first() = CanvasRenderingContext2DState::create();
-  m_path.clear();
-  if (SkCanvas* c = canvas()->existingDrawingCanvas()) {
-    // The canvas should always have an initial/unbalanced save frame, which
-    // we use to reset the top level matrix and clip here.
-    DCHECK_EQ(c->getSaveCount(), 2);
-    c->restore();
-    c->save();
-    DCHECK(c->getTotalMatrix().isIdentity());
-#if DCHECK_IS_ON()
-    SkIRect clipBounds;
-    DCHECK(c->getClipDeviceBounds(&clipBounds));
-    DCHECK(clipBounds == c->imageInfo().bounds());
-#endif
-  }
-  validateStateStack();
+  // This is a multiple inherritance bootstrap
+  BaseRenderingContext2D::reset();
 }
 
 void CanvasRenderingContext2D::restoreCanvasMatrixClipStack(SkCanvas* c) const {
   restoreMatrixClipStack(c);
 }
 
 bool CanvasRenderingContext2D::shouldAntialias() const {
   return state().shouldAntialias();
 }
 
@@ skipping 868 matching lines @@
   }
   return true;
 }
 
 void CanvasRenderingContext2D::resetUsageTracking() {
   UsageCounters newCounters;
   m_usageCounters = newCounters;
 }
 
 }  // namespace blink