[Extensions Bindings] Add an ExceptionHandler class

extensions/renderer/bindings/api_request_handler.h

 // Copyright 2016 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 EXTENSIONS_RENDERER_BINDINGS_API_REQUEST_HANDLER_H_
 #define EXTENSIONS_RENDERER_BINDINGS_API_REQUEST_HANDLER_H_
 
 #include <map>
 #include <memory>
 #include <set>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "extensions/renderer/bindings/api_binding_types.h"
 #include "extensions/renderer/bindings/api_last_error.h"
 #include "third_party/WebKit/public/web/WebUserGestureToken.h"
 #include "v8/include/v8.h"
 
 namespace base {
 class ListValue;
 }
 
 namespace extensions {
+class ExceptionHandler;
 
 // A wrapper around a map for extension API calls. Contains all pending requests
 // and the associated context and callback. Designed to be used on a single
 // thread, but amongst multiple contexts.
 class APIRequestHandler {
  public:
   // TODO(devlin): We may want to coalesce this with the
   // ExtensionHostMsg_Request_Params IPC struct.
   struct Request {
     Request();
@@ skipping 13 matching lines @@
   using SendRequestMethod =
       base::Callback<void(std::unique_ptr<Request>, v8::Local<v8::Context>)>;
 
   using CallJSFunction = base::Callback<void(v8::Local<v8::Function>,
                                              v8::Local<v8::Context>,
                                              int argc,
                                              v8::Local<v8::Value>[])>;
 
   APIRequestHandler(const SendRequestMethod& send_request,
                     const CallJSFunction& call_js,
-                    APILastError last_error);
+                    APILastError last_error,
+                    ExceptionHandler* exception_handler);
   ~APIRequestHandler();
 
   // Begins the process of processing the request. Returns the identifier of the
   // pending request, or -1 if no pending request was added (which can happen if
   // no callback was specified).
   int StartRequest(v8::Local<v8::Context> context,
                    const std::string& method,
                    std::unique_ptr<base::ListValue> arguments,
                    v8::Local<v8::Function> callback,
                    v8::Local<v8::Function> custom_callback,
@@ skipping 52 matching lines @@
   SendRequestMethod send_request_;
 
   // The method to call into a JS with specific arguments. We curry this in
   // because the manner we want to do this is a unittest (e.g.
   // v8::Function::Call) can be significantly different than in production
   // (where we have to deal with e.g. blocking javascript).
   CallJSFunction call_js_;
 
   APILastError last_error_;
 
+  // The exception handler for the bindings system; guaranteed to be valid
+  // during this object's lifetime.
+  ExceptionHandler* const exception_handler_;
+
   DISALLOW_COPY_AND_ASSIGN(APIRequestHandler);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_BINDINGS_API_REQUEST_HANDLER_H_