Refactor GvrDelegate ownership into GvrDelegateProvider and fix more threading violations.

chrome/browser/android/vr_shell/vr_gl_thread.h

 // Copyright 2016 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 CHROME_BROWSER_ANDROID_VR_SHELL_VR_GL_THREAD_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_VR_GL_THREAD_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 13 matching lines @@
   VrGLThread(
       const base::WeakPtr<VrShell>& weak_vr_shell,
       const base::WeakPtr<VrShellDelegate>& delegate_provider,
       scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner,
       gvr_context* gvr_api,
       bool initially_web_vr,
       bool reprojected_rendering);
 
   ~VrGLThread() override;
   base::WeakPtr<VrShellGl> GetVrShellGl() { return weak_vr_shell_gl_; }
-  VrShellGl* GetVrShellGlUnsafe() { return vr_shell_gl_.get(); }
 
  protected:
   void Init() override;
   void CleanUp() override;
 
  private:
   // Created on GL thread.
   std::unique_ptr<VrShellGl> vr_shell_gl_;
   base::WeakPtr<VrShellGl> weak_vr_shell_gl_;
 
   // This state is used for initializing vr_shell_gl_.
   base::WeakPtr<VrShell> weak_vr_shell_;
   base::WeakPtr<VrShellDelegate> delegate_provider_;
   scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
   gvr_context* gvr_api_;
   bool initially_web_vr_;
   bool reprojected_rendering_;
 
   DISALLOW_COPY_AND_ASSIGN(VrGLThread);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_VR_GL_THREAD_H_