Web setting for canvas2d msaa

Source/core/platform/graphics/chromium/Canvas2DLayerBridge.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 41 matching lines @@
     }
 }
 
 Canvas2DLayerBridgePtr& Canvas2DLayerBridgePtr::operator=(const PassRefPtr<Canvas2DLayerBridge>& other)
 {
     clear();
     m_ptr = other;
     return *this;
 }
 
-static SkSurface* createSurface(GraphicsContext3D* context3D, const IntSize& size)
+static SkSurface* createSurface(GraphicsContext3D* context3D, const IntSize& size, int msaaSampleCount)
 {
     ASSERT(!context3D->webContext()->isContextLost());
     GrContext* gr = context3D->grContext();
     if (!gr)
         return 0;
     gr->resetContext();
     SkImage::Info info;
     info.fWidth = size.width();
     info.fHeight = size.height();
     info.fColorType = SkImage::kPMColor_ColorType;
     info.fAlphaType = kPremul_SkAlphaType;
-    return SkSurface::NewRenderTarget(gr, info);
+    return SkSurface::NewRenderTarget(gr, info,  msaaSampleCount);
 }
 
-PassRefPtr<Canvas2DLayerBridge> Canvas2DLayerBridge::create(PassRefPtr<GraphicsContext3D> context, const IntSize& size, OpacityMode opacityMode)
+PassRefPtr<Canvas2DLayerBridge> Canvas2DLayerBridge::create(PassRefPtr<GraphicsContext3D> context, const IntSize& size, OpacityMode opacityMode, int msaaSampleCount)
 {
     TRACE_EVENT_INSTANT0("test_gpu", "Canvas2DLayerBridgeCreation");
-    SkAutoTUnref<SkSurface> surface(createSurface(context.get(), size));
+    SkAutoTUnref<SkSurface> surface(createSurface(context.get(), size, msaaSampleCount));
     if (!surface.get()) {
         return PassRefPtr<Canvas2DLayerBridge>();
     }
     RefPtr<SkDeferredCanvas> canvas = adoptRef(SkDeferredCanvas::Create(surface.get()));
     RefPtr<Canvas2DLayerBridge> layerBridge = adoptRef(new Canvas2DLayerBridge(context, canvas.release(), opacityMode));
     return layerBridge.release();
 }
 
 Canvas2DLayerBridge::Canvas2DLayerBridge(PassRefPtr<GraphicsContext3D> context, PassRefPtr<SkDeferredCanvas> canvas, OpacityMode opacityMode)
     : m_canvas(canvas)
@@ skipping 159 matching lines @@
     if (m_context->webContext()->isContextLost() || !m_surfaceIsValid) {
         // Attempt to recover.
         m_layer->clearTexture();
         m_mailboxes.clear();
         RefPtr<GraphicsContext3D> sharedContext = SharedGraphicsContext3D::get();
         if (!sharedContext || sharedContext->webContext()->isContextLost()) {
             m_surfaceIsValid = false;
         } else {
             m_context = sharedContext;
             IntSize size(m_canvas->getTopDevice()->width(), m_canvas->getTopDevice()->height());
-            SkAutoTUnref<SkSurface> surface(createSurface(m_context.get(), size));
+            int msaaSampleCount = m_canvas->getTopDevice()->accessRenderTarget()->desc().fSampleCnt;
+            SkAutoTUnref<SkSurface> surface(createSurface(m_context.get(), size, msaaSampleCount));
             if (surface.get()) {
                 m_canvas->setSurface(surface.get());
                 m_surfaceIsValid = true;
                 // FIXME: draw sad canvas picture into new buffer crbug.com/243842
             } else {
                 // Surface allocation failed. Set m_surfaceIsValid to false to
                 // trigger subsequent retry.
                 m_surfaceIsValid = false;
             }
         }
@@ skipping 145 matching lines @@
 Canvas2DLayerBridge::MailboxInfo::MailboxInfo(const MailboxInfo& other) {
     // This copy constructor should only be used for Vector reallocation
     // Assuming 'other' is to be destroyed, we swap m_image ownership
     // rather than do a refcount dance.
     memcpy(&m_mailbox, &other.m_mailbox, sizeof(m_mailbox));
     m_image.swap(const_cast<SkAutoTUnref<SkImage>*>(&other.m_image));
     m_status = other.m_status;
 }
 
 }