Make all quota-exceeding messages in the storage API explain what the failure

chrome/browser/extensions/extension_function_dispatcher.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 "chrome/browser/extensions/extension_function_dispatcher.h"
 
 #include <map>
 
 #include "base/json/json_string_value_serializer.h"
 #include "base/lazy_instance.h"
@@ skipping 134 matching lines @@
   if (!function_io) {
     NOTREACHED();
     return;
   }
   function_io->set_ipc_sender(ipc_sender, routing_id);
   function_io->set_extension_info_map(extension_info_map);
   function->set_include_incognito(
       extension_info_map->IsIncognitoEnabled(extension->id()));
 
   ExtensionsQuotaService* quota = extension_info_map->GetQuotaService();
-  if (quota->Assess(extension->id(), function, &params.arguments,
-                    base::TimeTicks::Now())) {
+  std::string violation_error = quota->Assess(extension->id(),
+                                              function,
+                                              &params.arguments,
+                                              base::TimeTicks::Now());
+  if (violation_error.empty()) {
     function->Run();
     LogSuccess(extension, params);
   } else {
-    function->OnQuotaExceeded();
+    function->OnQuotaExceeded(violation_error);
     LogFailure(extension, params.name, kQuotaExceeded);
   }
 }
 
 ExtensionFunctionDispatcher::ExtensionFunctionDispatcher(Profile* profile,
                                                          Delegate* delegate)
   : profile_(profile),
     delegate_(delegate) {
 }
 
@@ skipping 31 matching lines @@
       function->AsUIThreadExtensionFunction();
   if (!function_ui) {
     NOTREACHED();
     return;
   }
   function_ui->set_dispatcher(AsWeakPtr());
   function_ui->set_profile(profile_);
   function->set_include_incognito(service->CanCrossIncognito(extension));
 
   ExtensionsQuotaService* quota = service->quota_service();
-  if (quota->Assess(extension->id(), function, &params.arguments,
-                    base::TimeTicks::Now())) {
+  std::string violation_error = quota->Assess(extension->id(),
+                                              function,
+                                              &params.arguments,
+                                              base::TimeTicks::Now());
+  if (violation_error.empty()) {
     // See crbug.com/39178.
     ExternalProtocolHandler::PermitLaunchUrl();
 
     function->Run();
     LogSuccess(extension, params);
   } else {
-    function->OnQuotaExceeded();
+    function->OnQuotaExceeded(violation_error);
     LogFailure(extension, params.name, kQuotaExceeded);
   }
 
   // Check if extension was uninstalled by management.uninstall.
   if (!service->extensions()->GetByID(params.extension_id))
     return;
 
   // We only adjust the keepalive count for UIThreadExtensionFunction for
   // now, largely for simplicity's sake. This is OK because currently, only
   // the webRequest API uses IOThreadExtensionFunction, and that API is not
@@ skipping 61 matching lines @@
 }
 
 // static
 void ExtensionFunctionDispatcher::SendAccessDenied(
     IPC::Sender* ipc_sender, int routing_id, int request_id) {
   ListValue empty_list;
   ipc_sender->Send(new ExtensionMsg_Response(
       routing_id, request_id, false, empty_list,
       "Access to extension API denied."));
 }