Remove const qualifier from function return type

components/copresence/rpc/rpc_handler_unittest.cc

 // 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.
 
 #include "components/copresence/rpc/rpc_handler.h"
 
 #include <map>
 #include <string>
 #include <vector>
 
@@ skipping 57 matching lines @@
   }
 
   void HandleStatusUpdate(CopresenceStatus /* status */) override {
     NOTREACHED();
   }
 
   net::URLRequestContextGetter* GetRequestContext() const override {
     return nullptr;
   }
 
-  const std::string GetPlatformVersionString() const override {
+  std::string GetPlatformVersionString() const override {
     return kChromeVersion;
   }
 
-  const std::string GetAPIKey(const std::string& app_id) const override {
+  std::string GetAPIKey(const std::string& app_id) const override {
     return app_id + " API Key";
   }
 
   WhispernetClient* GetWhispernetClient() override {
     return whispernet_client_.get();
   }
 
   // TODO(ckehoe): Add GCM tests.
   gcm::GCMDriver* GetGCMDriver() override {
     return nullptr;
   }
 
-  const std::string GetDeviceId(bool authenticated) override {
+  std::string GetDeviceId(bool authenticated) override {
     return device_id_by_auth_state_[authenticated];
   }
 
   void SaveDeviceId(bool authenticated, const std::string& device_id) override {
     device_id_by_auth_state_[authenticated] = device_id;
   }
 
  protected:
 
   // Send test input to RpcHandler
@@ skipping 232 matching lines @@
   // Check processing.
   status_ = FAIL;
   SendReportResponse(net::HTTP_OK, response.Pass());
   EXPECT_EQ(SUCCESS, status_);
   EXPECT_TRUE(TokenIsInvalid("bad token"));
   EXPECT_THAT(directive_handler_.added_directives(),
               ElementsAre("Subscription 1", "Subscription 2"));
 }
 
 }  // namespace copresence