Fix screen mirroring on Chrome OS (ReflectorTexture partial swap)

content/browser/compositor/reflector_texture.h

 // Copyright 2015 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 CONTENT_BROWSER_COMPOSITOR_REFLECTOR_TEXTURE_H_
 #define CONTENT_BROWSER_COMPOSITOR_REFLECTOR_TEXTURE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 20 matching lines @@
 
 // Create and manages texture mailbox to be used by Reflector.
 class CONTENT_EXPORT ReflectorTexture {
  public:
   explicit ReflectorTexture(cc::ContextProvider* provider);
   ~ReflectorTexture();
 
   void CopyTextureFullImage(const gfx::Size& size);
   void CopyTextureSubImage(const gfx::Rect& size);
 
+  bool is_texture_defined() const { return is_texture_defined_; }
+
   uint32_t texture_id() const { return texture_id_; }
   scoped_refptr<OwnedMailbox> mailbox() { return mailbox_; }
 
  private:
   scoped_refptr<OwnedMailbox> mailbox_;
   std::unique_ptr<display_compositor::GLHelper> gl_helper_;
   uint32_t texture_id_;
+  bool is_texture_defined_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(ReflectorTexture);
 };
 
 }  // namespace content
 
 #endif