Change TraceDataEndPoint::ReceiveTraceChunk() to accept unique_ptr<string>

content/browser/tracing/tracing_controller_browsertest.cc

 // 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.
 
 #include "content/public/browser/tracing_controller.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/files/file_util.h"
@@ skipping 47 matching lines @@
 
 }  // namespace
 
 class TracingControllerTestEndpoint : public TraceDataEndpoint {
  public:
   TracingControllerTestEndpoint(
       base::Callback<void(std::unique_ptr<const base::DictionaryValue>,
                           base::RefCountedString*)> done_callback)
       : done_callback_(done_callback) {}
 
-  void ReceiveTraceChunk(const std::string& chunk) override {
-    EXPECT_FALSE(chunk.empty());
-    trace_ += chunk;
+  void ReceiveTraceChunk(std::unique_ptr<std::string> chunk) override {
+    EXPECT_FALSE(chunk->empty());
+    trace_ += *chunk;
   }
 
   void ReceiveTraceFinalContents(
       std::unique_ptr<const base::DictionaryValue> metadata) override {
     scoped_refptr<base::RefCountedString> chunk_ptr =
         base::RefCountedString::TakeString(&trace_);
 
     BrowserThread::PostTask(
         BrowserThread::UI, FROM_HERE,
         base::Bind(done_callback_, base::Passed(std::move(metadata)),
@@ skipping 354 matching lines @@
 
   TracingController* controller = TracingController::GetInstance();
   EXPECT_TRUE(controller->StartTracing(
       TraceConfig(),
       TracingController::StartTracingDoneCallback()));
   EXPECT_TRUE(controller->StopTracing(NULL));
   base::RunLoop().RunUntilIdle();
 }
 
 }  // namespace content