Split WebGraphicsContext3DCommandBufferImpl::initialize() into two stages.

content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h

Index: content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h
===================================================================
--- content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h	(revision 98270)
+++ content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h	(working copy)
@@ -12,6 +12,7 @@
 
 #include "base/memory/scoped_ptr.h"
 #include "content/renderer/gpu/renderer_gl_context.h"
+#include "googleurl/src/gurl.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebGraphicsContext3D.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebString.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
@@ -57,6 +58,10 @@
                           WebKit::WebView*,
                           bool renderDirectlyToWebView);
 
+  // Must be called after initialize() and before any of the following methods.
+  // Binds this object to the current thread. We can't bind to multiple threads.
+  // TODO(husky): Document threading restrictions in WebGraphicsContext3D.h,
+  // enforce strictly in all implementations.

[jbates, 2011/08/26 17:12:47]

This is a bit confusing, can it be rephrased?
"Permanently binds to the first calling thread. Returns false if the graphics
context fails to create. Does not do any thread checking on consecutive calls --
the return value will may remain true even when called from the wrong thread."

   virtual bool makeContextCurrent();
 
   virtual int width();
@@ -431,6 +436,12 @@
           WebGraphicsSwapBuffersCompleteCallbackCHROMIUM* callback);
 
  private:
+  // Initialize the underlying GL context. May be called multiple times; second
+  // and subsequent calls are ignored. Must be called from the thread that is
+  // going to use this object to issue GL commands (which might not be the main
+  // thread).
+  bool MaybeInitializeGL();
+
   // SwapBuffers callback.
   void OnSwapBuffersComplete();
   virtual void OnContextLost(RendererGLContext::ContextLostReason reason);
@@ -440,6 +451,11 @@
   // The GLES2Implementation we use for OpenGL rendering.
   gpu::gles2::GLES2Implementation* gl_;
 
+  // State needed by InitializeGLES2.
+  GpuChannelHost* host_;
+  GURL active_url_;
+  int32 render_view_routing_id_;
+
   bool render_directly_to_web_view_;
 #ifndef WTF_USE_THREADED_COMPOSITING
   // If rendering directly to WebView, weak pointer to it.