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

chrome/browser/extensions/extension_function.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_H_
 
 #include <list>
 #include <string>
 
@@ skipping 100 matching lines @@
   // this function to |heuristics|. The ownership of the new QuotaLimitHeuristic
   // instances is passed to the owner of |heuristics|.
   // No quota limiting by default.
   //
   // Only called once per lifetime of the ExtensionsQuotaService.
   virtual void GetQuotaLimitHeuristics(
       QuotaLimitHeuristics* heuristics) const {}
 
   // Called when the quota limit has been exceeded. The default implementation
   // returns an error.
-  virtual void OnQuotaExceeded();
+  virtual void OnQuotaExceeded(const std::string& violation_error);
 
   // Specifies the raw arguments to the function, as a JSON value.
   virtual void SetArgs(const base::ListValue* args);
 
   // Sets a single Value as the results of the function.
   void SetResult(base::Value* result);
 
   // Retrieves the results of the function as a ListValue.
   const base::ListValue* GetResultList();
 
@@ skipping 311 matching lines @@
  public:
   SyncIOThreadExtensionFunction();
 
   virtual void Run() OVERRIDE;
 
  protected:
   virtual ~SyncIOThreadExtensionFunction();
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_H_