Retry 3 to split WebGraphicsContext3DCommandBufferImpl::initialize() into two stages.

content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h

Index: content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h
diff --git a/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h b/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h
index 0749fa74e41e7a0f0e20bab7ad1acdd450b987db..e2afb4ff22ae9fd756f708a7a0681738840117a0 100644
--- a/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h
+++ b/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.h
@@ -13,6 +13,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/task.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"
@@ -58,6 +59,11 @@ class WebGraphicsContext3DCommandBufferImpl
                           WebKit::WebView*,
                           bool renderDirectlyToWebView);
 
+  // Must be called after initialize() and before any of the following methods.
+  // Permanently binds to the first calling thread. Returns false if the
+  // graphics context fails to create. Do not call from more than one thread.
+  // TODO(husky): Document threading restrictions in WebGraphicsContext3D.h,

[lain Merrick, 2011/09/09 10:42:47]

Is this TODO still accurate? Happy to pick it up, I just want to check that's
still a good approach. Also, Gregg's idea of merging the three implementations
should make our lives much easier.

[nduca, 2011/09/09 15:47:19]

I'll land a comment on the WebGraphicsContext.h side, since this patch pairs
with a webkit-side change. @kbr and I talked this approach through, though we
also considered an option of making delaying makeCurrent a property on the
Attributes structure. I'm down doing either approach, what do you think makes
more sense?

+  // enforce strictly in all implementations.
   virtual bool makeContextCurrent();
 
   virtual int width();
@@ -437,6 +443,12 @@ class WebGraphicsContext3DCommandBufferImpl
 #endif
 
  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);
@@ -446,6 +458,11 @@ class WebGraphicsContext3DCommandBufferImpl
   // The GLES2Implementation we use for OpenGL rendering.
   gpu::gles2::GLES2Implementation* gl_;
 
+  // State needed by MaybeInitializeGL.
+  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.