Move ReadFileToString to the base namespace.

chrome/browser/extensions/api/messaging/native_message_process_host_unittest.cc

 // Copyright (c) 2012 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 "base/bind.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/json/json_reader.h"
@@ skipping 177 matching lines @@
       0, launcher.Pass());
   ASSERT_TRUE(native_message_process_host_.get());
   base::RunLoop().RunUntilIdle();
 
   native_message_process_host_->Send(kTestMessage);
   base::RunLoop().RunUntilIdle();
 
   std::string output;
   base::TimeTicks start_time = base::TimeTicks::Now();
   while (base::TimeTicks::Now() - start_time < TestTimeouts::action_timeout()) {
-    ASSERT_TRUE(file_util::ReadFileToString(temp_output_file, &output));
+    ASSERT_TRUE(base::ReadFileToString(temp_output_file, &output));
     if (!output.empty())
       break;
     base::PlatformThread::YieldCurrentThread();
   }
 
   EXPECT_EQ(FormatMessage(kTestMessage), output);
 }
 
 // Test send message with a real client. The client just echo's back the text
 // it received.
@@ skipping 37 matching lines @@
   read_message_run_loop_->Run();
   EXPECT_TRUE(last_message_parsed_->GetInteger("id", &id));
   EXPECT_EQ(2, id);
   EXPECT_TRUE(last_message_parsed_->GetString("echo.foo", &text));
   EXPECT_EQ("bar", text);
   EXPECT_TRUE(last_message_parsed_->GetString("caller_url", &url));
   EXPECT_EQ(expected_url, url);
 }
 
 }  // namespace extensions