GCM Engine: Split up reg/unreg UNKNOWN_ERROR to improve metrics

google_apis/gcm/engine/gcm_unregistration_request_handler.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 "google_apis/gcm/engine/gcm_unregistration_request_handler.h"
 
 #include "base/macros.h"
 #include "base/metrics/histogram.h"
 #include "google_apis/gcm/base/gcm_util.h"
 #include "net/url_request/url_fetcher.h"
 
 namespace gcm {
 
 namespace {
 
 // Request constants.
 const char kUnregistrationCallerKey[] = "gcm_unreg_caller";
 // We are going to set the value to "false" in order to forcefully unregister
 // the application.
 const char kUnregistrationCallerValue[] = "false";
 
 // Response constants.
 const char kDeletedPrefix[] = "deleted=";
-const char kErrorPrefix[] = "Error=";
-const char kInvalidParameters[] = "INVALID_PARAMETERS";
 
 }  // namespace
 
 GCMUnregistrationRequestHandler::GCMUnregistrationRequestHandler(
     const std::string& app_id)
     : app_id_(app_id) {
 }
 
 GCMUnregistrationRequestHandler::~GCMUnregistrationRequestHandler() {}
 
 void GCMUnregistrationRequestHandler::BuildRequestBody(std::string* body){
   BuildFormEncoding(kUnregistrationCallerKey, kUnregistrationCallerValue, body);
 }
 
 UnregistrationRequest::Status GCMUnregistrationRequestHandler::ParseResponse(
-    const net::URLFetcher* source) {
-  std::string response;
-  if (!source->GetResponseAsString(&response)) {
-    DVLOG(1) << "Failed to get response body.";
-    return UnregistrationRequest::NO_RESPONSE_BODY;
-  }
-
+    const std::string& response) {
   DVLOG(1) << "Parsing unregistration response.";
   if (response.find(kDeletedPrefix) != std::string::npos) {
     std::string deleted_app_id = response.substr(
         response.find(kDeletedPrefix) + arraysize(kDeletedPrefix) - 1);
     return deleted_app_id == app_id_ ?
         UnregistrationRequest::SUCCESS :
         UnregistrationRequest::INCORRECT_APP_ID;
   }
 
-  if (response.find(kErrorPrefix) != std::string::npos) {
-    std::string error = response.substr(
-        response.find(kErrorPrefix) + arraysize(kErrorPrefix) - 1);
-   return error == kInvalidParameters ?
-        UnregistrationRequest::INVALID_PARAMETERS :
-        UnregistrationRequest::UNKNOWN_ERROR;
-  }
-
   DVLOG(1) << "Not able to parse a meaningful output from response body."
            << response;
   return UnregistrationRequest::RESPONSE_PARSING_FAILED;
 }
 
 void GCMUnregistrationRequestHandler::ReportUMAs(
     UnregistrationRequest::Status status,
     int retry_count,
     base::TimeDelta complete_time) {
   UMA_HISTOGRAM_ENUMERATION("GCM.UnregistrationRequestStatus",
                             status,
                             UnregistrationRequest::UNREGISTRATION_STATUS_COUNT);
 
   // Other UMAs are only reported when the request succeeds.
   if (status != UnregistrationRequest::SUCCESS)
     return;
 
   UMA_HISTOGRAM_COUNTS("GCM.UnregistrationRetryCount", retry_count);
   UMA_HISTOGRAM_TIMES("GCM.UnregistrationCompleteTime", complete_time);
 }
 
 }  // namespace gcm