Replace source pointer in cc::CopyOutputRequest with a base::UnguessableToken

cc/output/copy_output_request.h

 // Copyright 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 CC_OUTPUT_COPY_OUTPUT_REQUEST_H_
 #define CC_OUTPUT_COPY_OUTPUT_REQUEST_H_
 
 #include <memory>
 
 #include "base/callback.h"
 #include "base/memory/ptr_util.h"
+#include "base/optional.h"
+#include "base/unguessable_token.h"
 #include "cc/base/cc_export.h"
 #include "cc/resources/single_release_callback.h"
 #include "cc/resources/texture_mailbox.h"
 #include "ui/gfx/geometry/rect.h"
 
 class SkBitmap;
 
 namespace cc {
 class CopyOutputResult;
 
@@ skipping 14 matching lines @@
     return base::WrapUnique(new CopyOutputRequest(true, result_callback));
   }
   static std::unique_ptr<CopyOutputRequest> CreateRelayRequest(
       const CopyOutputRequest& original_request,
       const CopyOutputRequestCallback& result_callback);
 
   ~CopyOutputRequest();
 
   bool IsEmpty() const { return result_callback_.is_null(); }
 
-  // Optionally specify the source of this copy request.  If set when this copy
+  // Optionally specify the source of this copy request. If set when this copy
   // request is submitted to a layer, a prior uncommitted copy request from the
-  // same |source| will be aborted.
-  void set_source(void* source) { source_ = source; }
-  void* source() const { return source_; }
+  // same source will be aborted.
+  void set_source(const base::UnguessableToken& source) { source_ = source; }
+  bool has_source() const { return source_.has_value(); }
+  const base::UnguessableToken& source() const { return *source_; }
 
   bool force_bitmap_result() const { return force_bitmap_result_; }
 
   // By default copy requests copy the entire layer's subtree output. If an
   // area is given, then the intersection of this rect (in layer space) with
   // the layer's subtree output will be returned.
   void set_area(const gfx::Rect& area) {
     has_area_ = true;
     area_ = area;
   }
@@ skipping 14 matching lines @@
       const TextureMailbox& texture_mailbox,
       std::unique_ptr<SingleReleaseCallback> release_callback);
 
   void SendResult(std::unique_ptr<CopyOutputResult> result);
 
  private:
   CopyOutputRequest();
   CopyOutputRequest(bool force_bitmap_result,
                     const CopyOutputRequestCallback& result_callback);
 
-  void* source_;
+  base::Optional<base::UnguessableToken> source_;
   bool force_bitmap_result_;
   bool has_area_;
   bool has_texture_mailbox_;
   gfx::Rect area_;
   TextureMailbox texture_mailbox_;
   CopyOutputRequestCallback result_callback_;
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_COPY_OUTPUT_REQUEST_H_