Remove needless move() calls in cloud_print/gcp20

After https://codereview.chromium.org/1553493002/, the compiler can
inform us that these are not needed and in fact harmful:

..\..\cloud_print\gcp20\prototype\privet_http_server.cc(418,10) :  error: moving a local object in a return statement prevents copy elision [-Werror,-Wpessimizing-move]
  return std::move(response);
         ^
..\..\cloud_print\gcp20\prototype\privet_http_server.cc(418,10) :  note: remove std::move call here
  return std::move(response);
         ^~~~~~~~~~

..\..\cloud_print\gcp20\prototype\cloud_print_url_request_context_getter.cc(30,16) :  error: moving a temporary object prevents copy elision [-Werror,-Wpessimizing-move]
    context_ = std::move(builder.Build());
               ^
..\..\cloud_print\gcp20\prototype\cloud_print_url_request_context_getter.cc(30,16) :  note: remove std::move call here
    context_ = std::move(builder.Build());
               ^~~~~~~~~~               ~

BUG=82385
TBR=vitalybuka

Review URL: https://codereview.chromium.org/1552613003 .

Cr-Commit-Position: refs/heads/master@{#367067}

cloud_print/gcp20/prototype/cloud_print_request.cc

@@ -57,7 +57,7 @@ scoped_ptr<CloudPrintRequest> CloudPrintRequest::CreatePost(
   scoped_ptr<CloudPrintRequest> request(
       new CloudPrintRequest(url, URLFetcher::POST, delegate));
   request->fetcher_->SetUploadData(mimetype, content);
-  return std::move(request);
+  return request;
 }
 
 void CloudPrintRequest::Run(

cloud_print/gcp20/prototype/cloud_print_url_request_context_getter.cc

@@ -27,7 +27,7 @@ CloudPrintURLRequestContextGetter::GetURLRequestContext() {
     builder.set_proxy_config_service(
         make_scoped_ptr(new net::ProxyConfigServiceFixed(net::ProxyConfig())));
 #endif  // defined(OS_LINUX) || defined(OS_ANDROID)
-    context_ = std::move(builder.Build());
+    context_ = builder.Build();
   }
   return context_.get();
 }

cloud_print/gcp20/prototype/privet_http_server.cc

@@ -35,7 +35,7 @@ scoped_ptr<base::DictionaryValue> CreateError(const std::string& error_type) {
   scoped_ptr<base::DictionaryValue> error(new base::DictionaryValue);
   error->SetString("error", error_type);
 
-  return std::move(error);
+  return error;
 }
 
 // {"error":|error_type|, "description":|description|}
@@ -44,7 +44,7 @@ scoped_ptr<base::DictionaryValue> CreateErrorWithDescription(
     const std::string& description) {
   scoped_ptr<base::DictionaryValue> error(CreateError(error_type));
   error->SetString("description", description);
-  return std::move(error);
+  return error;
 }
 
 // {"error":|error_type|, "timeout":|timeout|}
@@ -53,7 +53,7 @@ scoped_ptr<base::DictionaryValue> CreateErrorWithTimeout(
     int timeout) {
   scoped_ptr<base::DictionaryValue> error(CreateError(error_type));
   error->SetInteger("timeout", timeout);
-  return std::move(error);
+  return error;
 }
 
 // Converts state to string.
@@ -278,7 +278,7 @@ scoped_ptr<base::DictionaryValue> PrivetHttpServer::ProcessInfo(
   response->Set("type", type.DeepCopy());
 
   *status_code = net::HTTP_OK;
-  return std::move(response);
+  return response;
 }
 
 scoped_ptr<base::DictionaryValue> PrivetHttpServer::ProcessCapabilities(
@@ -377,7 +377,7 @@ scoped_ptr<base::DictionaryValue> PrivetHttpServer::ProcessSubmitDoc(
           base::StringPrintf("%u", static_cast<uint32_t>(job.content.size())));
       if (job_name_present)
         response->SetString("job_name", job.job_name);
-      return std::move(response);
+      return response;
 
     case LocalPrintJob::SAVE_INVALID_PRINT_JOB:
       return CreateErrorWithTimeout("invalid_print_job", timeout);
@@ -415,7 +415,7 @@ scoped_ptr<base::DictionaryValue> PrivetHttpServer::ProcessJobState(
   response->SetString("job_id", job_id);
   response->SetString("state", LocalPrintJobStateToString(info.state));
   response->SetInteger("expires_in", info.expires_in);
-  return std::move(response);
+  return response;
 }
 
 scoped_ptr<base::DictionaryValue> PrivetHttpServer::ProcessRegister(
@@ -466,7 +466,7 @@ scoped_ptr<base::DictionaryValue> PrivetHttpServer::ProcessRegister(
 
   ProcessRegistrationStatus(status, &response);
   *status_code = net::HTTP_OK;
-  return std::move(response);
+  return response;
 }
 
 void PrivetHttpServer::ProcessRegistrationStatus(