Implement offscreenCanvas.getContext('webgl') on a worker thread

third_party/WebKit/public/platform/Platform.h

 /*
  * 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 445 matching lines @@
         unsigned processCrashCount = 0;
         unsigned resetNotificationStrategy = 0;
         bool sandboxed = false;
         bool amdSwitchable = false;
         bool optimus = false;
         WebString vendorInfo;
         WebString rendererInfo;
         WebString driverVersion;
         WebString errorMessage;
     };
+    enum WillBindToCurrentThread {
+        BindToCurrentThread,
+        DoNotBindToCurrentThread
+    };
     // Returns a newly allocated and initialized offscreen context provider,
     // backed by an independent context. Returns null if the context cannot be
     // created or initialized.
     // Passing an existing provider to shareContext will create the new context
     // in the same share group as the one passed.
     virtual WebGraphicsContext3DProvider* createOffscreenGraphicsContext3DProvider(
         const ContextAttributes&,
         const WebURL& topDocumentURL,
         WebGraphicsContext3DProvider* shareContext,
-        GraphicsInfo*) { return nullptr; }
+        GraphicsInfo*,
+        WillBindToCurrentThread) { return nullptr; }
 
     // Returns a newly allocated and initialized offscreen context provider,
     // backed by the process-wide shared main thread context. Returns null if
     // the context cannot be created or initialized.
     virtual WebGraphicsContext3DProvider* createSharedOffscreenGraphicsContext3DProvider() { return nullptr; }
 
     // Returns true if the platform is capable of producing an offscreen context suitable for accelerating 2d canvas.
     // This will return false if the platform cannot promise that contexts will be preserved across operations like
     // locking the screen or if the platform cannot provide a context with suitable performance characteristics.
     //
@@ skipping 135 matching lines @@
 protected:
     Platform();
     virtual ~Platform() { }
 
     WebThread* m_mainThread;
 };
 
 } // namespace blink
 
 #endif