gpu: Remove WebGraphicsContext3D::makeContextCurrent() in Blink

Source/core/html/canvas/WebGLRenderingContext.cpp

 /*
  * Copyright (C) 2009 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 67 matching lines @@
         return nullptr;
     }
 
     // The only situation that attrs is null is through Document::getCSSCanvasContext().
     RefPtrWillBeRawPtr<WebGLContextAttributes> defaultAttrs = nullptr;
     if (!attrs) {
         defaultAttrs = WebGLContextAttributes::create();
         attrs = defaultAttrs.get();
     }
     blink::WebGraphicsContext3D::Attributes attributes = attrs->attributes(document.topDocument().url().string(), settings, 1);
     OwnPtr<blink::WebGraphicsContext3D> context = adoptPtr(blink::Platform::current()->createOffscreenGraphicsContext3D(attributes, 0));

[dshwang, 2014/08/16 15:21:27]

chromium doesn't do initial bind unlike
createSharedOffscreenGraphicsContext3D().

-    if (!context || !context->makeContextCurrent()) {
+    if (!context) {
         canvas->dispatchEvent(WebGLContextEvent::create(EventTypeNames::webglcontextcreationerror, false, true, "Could not create a WebGL context."));
         return nullptr;
     }
 
     OwnPtr<Extensions3DUtil> extensionsUtil = Extensions3DUtil::create(context.get());
     if (!extensionsUtil)
         return nullptr;
     if (extensionsUtil->supportsExtension("GL_EXT_debug_marker"))
         context->pushGroupMarkerEXT("WebGLRenderingContext");
 
@@ skipping 67 matching lines @@
     visitor->trace(m_webglDrawBuffers);
     visitor->trace(m_webglCompressedTextureATC);
     visitor->trace(m_webglCompressedTextureETC1);
     visitor->trace(m_webglCompressedTexturePVRTC);
     visitor->trace(m_webglCompressedTextureS3TC);
     visitor->trace(m_webglDepthTexture);
     WebGLRenderingContextBase::trace(visitor);
 }
 
 } // namespace blink