Accelerate small canvases if Ganesh is on.

Blink half of change.

BUG=382738

Review URL: https://codereview.chromium.org/328883002

git-svn-id: svn://svn.chromium.org/blink/trunk@175934 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp

@@ -43,6 +43,7 @@
 #include "core/html/canvas/WebGLContextAttributes.h"
 #include "core/html/canvas/WebGLContextEvent.h"
 #include "core/html/canvas/WebGLRenderingContext.h"
+#include "core/page/ChromeClient.h"
 #include "core/rendering/RenderHTMLCanvas.h"
 #include "platform/MIMETypeRegistry.h"
 #include "platform/graphics/Canvas2DImageBufferSurface.h"
@@ -431,8 +432,9 @@ bool HTMLCanvasElement::shouldAccelerate(const IntSize& size) const
     if (!settings || !settings->accelerated2dCanvasEnabled())
         return false;
 
-    // Do not use acceleration for small canvas.
-    if (size.width() * size.height() < settings->minimumAccelerated2dCanvasSize())
+    // Do not use acceleration for small canvases, unless GPU rasterization is available.
+    // GPU raterization is a heuristic to avoid difficult content & whitelist targeted content.
+    if (!document().frame()->chromeClient().usesGpuRasterization() && size.width() * size.height() < settings->minimumAccelerated2dCanvasSize())
         return false;
 
     if (!blink::Platform::current()->canAccelerate2dCanvas())

third_party/WebKit/Source/core/loader/EmptyClients.h

@@ -161,6 +161,9 @@ public:
     virtual void annotatedRegionsChanged() OVERRIDE { }
     virtual bool paintCustomOverhangArea(GraphicsContext*, const IntRect&, const IntRect&, const IntRect&) OVERRIDE { return false; }
     virtual String acceptLanguages() OVERRIDE;
+
+    virtual bool usesGpuRasterization() OVERRIDE { return false; }
+
 };
 
 class EmptyFrameLoaderClient FINAL : public FrameLoaderClient {

third_party/WebKit/Source/core/page/ChromeClient.h

@@ -238,6 +238,8 @@ public:
     virtual void willSetInputMethodState() { }
     virtual void didUpdateTextOfFocusedElementByNonUserInput() { }
 
+    virtual bool usesGpuRasterization() = 0;
+
 protected:
     virtual ~ChromeClient() { }
 };

third_party/WebKit/Source/web/ChromeClientImpl.cpp

@@ -882,6 +882,11 @@ void ChromeClientImpl::openTextDataListChooser(HTMLInputElement& input)
         m_webView->autofillClient()->openTextDataListChooser(WebInputElement(&input));
 }
 
+bool ChromeClientImpl::usesGpuRasterization()
+{
+    return m_webView->layerTreeView()->usesGpuRasterization();
+}
+
 PassOwnPtr<NavigatorContentUtilsClientImpl> NavigatorContentUtilsClientImpl::create(WebViewImpl* webView)
 {
     return adoptPtr(new NavigatorContentUtilsClientImpl(webView));
@@ -907,4 +912,5 @@ void NavigatorContentUtilsClientImpl::unregisterProtocolHandler(const String& sc
     m_webView->client()->unregisterProtocolHandler(scheme, baseURL, url);
 }
 
+
 } // namespace blink

third_party/WebKit/Source/web/ChromeClientImpl.h

@@ -183,6 +183,8 @@ public:
     virtual void willSetInputMethodState() OVERRIDE;
     virtual void didUpdateTextOfFocusedElementByNonUserInput() OVERRIDE;
 
+    virtual bool usesGpuRasterization() OVERRIDE;
+
 private:
     virtual bool isChromeClientImpl() const OVERRIDE { return true; }
 

third_party/WebKit/public/platform/WebLayerTreeView.h

@@ -141,6 +141,9 @@ public:
 
     // Toggles scroll bottleneck rects on the HUD layer
     virtual void setShowScrollBottleneckRects(bool) { }
+
+    // FIXME: make pure virtual once the cc-side patch is in
+    virtual bool usesGpuRasterization() { return false; };
 };
 
 } // namespace blink