cc: Route offscreen context creation for compositor to the browser.

ui/gl/context_provider.h

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_GL_CONTEXT_PROVIDER_H_
+#define UI_GL_CONTEXT_PROVIDER_H_
+
+#include "base/memory/ref_counted.h"
+
+class GrContext;
+namespace WebKit { class WebGraphicsContext3D; }

[piman, 2013/02/21 22:49:48]

nit: It's a bit weird to have this file in ui/gl, and have ui/gl depend on
WebKit.
How about moving this file to webkit/gpu?

[danakj, 2013/02/22 01:56:31]

Oh, somehow I thought cc can't see webkit/gpu, but it can.. I'll try moving it
and see if anything blows up!

[danakj, 2013/02/22 01:59:28]

Or actually there's a TODO in our DEPS, which I guess was added with webkit/gpu
since I last looked.

Where else can this class could live then since it will outlive WGC3D?

+
+namespace ui {
+
+class ContextProvider : public base::RefCounted<ContextProvider> {

[piman, 2013/02/21 22:49:48]

RefCountedThreadSafe

[danakj, 2013/02/22 01:56:31]

Aahh ok!

+ public:
+  // Initialize and create a 3d context. This must be called from the main
+  // thread. Calling it more than once should have no effect.
+  virtual bool InitializeOnMainThread() = 0;
+
+  // Bind the 3d context to the current thread. This should be called before
+  // accessing the contexts. Calling it more than once should have no effect.
+  // Once this function has been called, the class should only be accessed
+  // from the same thread.
+  virtual bool BindToCurrentThread() = 0;
+
+  virtual WebKit::WebGraphicsContext3D* Context3d() = 0;
+  virtual class GrContext* GrContext() = 0;
+
+  // Ask the provider to check if the contexts are valid or lost. If they are,
+  // this should invalidate the provider so that it can be replaced with a new
+  // one.
+  virtual void VerifyContexts() = 0;
+
+ protected:
+  friend class base::RefCounted<ContextProvider>;
+  virtual ~ContextProvider() {}
+};
+
+}  // namespace ui
+
+#endif  // UI_GL_CONTEXT_PROVIDER_H_