Fix a bug so GPU blacklist for accelerated 2d canvas is honored.

BUG=97640
TEST=accelerated canvas 2d is truly blocked in linux
Review URL: http://codereview.chromium.org/7995011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@102400 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/tab_contents/render_view_host_delegate_helper.cc

@@ -491,6 +491,8 @@ WebPreferences RenderViewHostDelegateHelper::GetWebkitPrefs(
       web_prefs.accelerated_compositing_enabled = false;
     if (blacklist_flags & GpuFeatureFlags::kGpuFeatureWebgl)
       web_prefs.experimental_webgl_enabled = false;
+    if (blacklist_flags & GpuFeatureFlags::kGpuFeatureAccelerated2dCanvas)
+      web_prefs.accelerated_2d_canvas_enabled = false;
     if (blacklist_flags & GpuFeatureFlags::kGpuFeatureMultisampling)
       web_prefs.gl_multisampling_enabled = false;
   }