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 97725)
+++ 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"
@@ -431,6 +432,9 @@
           WebGraphicsSwapBuffersCompleteCallbackCHROMIUM* callback);
 
  private:
+  // Second stage init. Called from compositor thread via makeContextCurrent().

[jamesr, 2011/08/23 01:23:23]

I'm not in love with this comment.  It assumes a background knowledge from the
reader that is not obvious and it is incorrect for most contexts since only some
contexts are compositor context.

Can you explain instead what this function does, when it should be called, and
what the threading implications are?

[lain Merrick, 2011/08/23 01:31:03]

Sure, will do. I wanted *some* comment but kept it terse to match surrounding
code. Happy to make it more detailed.

+  bool InitializeGLES2();

[nduca, 2011/08/23 05:08:19]

Any other names for this bikeshed? ;)

InitializeChannel?

[lain Merrick, 2011/08/24 19:52:05]

I just went for InitializeGL. And on second thoughts it's nicer to allow
idempotent calls, so... MaybeInitializeGL.

+
   // SwapBuffers callback.
   void OnSwapBuffersComplete();
   virtual void OnContextLost(RendererGLContext::ContextLostReason reason);
@@ -440,6 +444,11 @@
   // 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.