Cleanup: make ExtensionRequestSender manage its IPC responses directly, rather

chrome/renderer/extensions/extension_request_sender.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/renderer/extensions/extension_request_sender.h"
 
 #include "base/values.h"
 #include "chrome/common/extensions/extension_messages.h"
 #include "chrome/renderer/extensions/chrome_v8_context.h"
 #include "chrome/renderer/extensions/chrome_v8_context_set.h"
 #include "chrome/renderer/extensions/extension_dispatcher.h"
+#include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/render_view.h"
 #include "content/public/renderer/v8_value_converter.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebSecurityOrigin.h"
 
 using content::V8ValueConverter;
 
 // Contains info relevant to a pending API request.
 struct PendingRequest {
  public :
   PendingRequest(v8::Persistent<v8::Context> context, const std::string& name,
                  const std::string& extension_id)
       : context(context), name(name), extension_id(extension_id) {
   }
 
   ~PendingRequest() {
     context.Dispose();
   }
 
   v8::Persistent<v8::Context> context;
   std::string name;
   std::string extension_id;
 };
 
 ExtensionRequestSender::ExtensionRequestSender(
     ExtensionDispatcher* extension_dispatcher,
     ChromeV8ContextSet* context_set)
     : extension_dispatcher_(extension_dispatcher),
-      context_set_(context_set) {
+      context_set_(context_set),
+      scoped_observer_(this),
+      next_request_id_(0) {
+  scoped_observer_.Add(content::RenderThread::Get());
 }
 
 ExtensionRequestSender::~ExtensionRequestSender() {
 }
 
+bool ExtensionRequestSender::OnControlMessageReceived(
+    const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(ExtensionRequestSender, message)
+    IPC_MESSAGE_HANDLER(ExtensionMsg_Response, OnExtensionResponse)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
 void ExtensionRequestSender::InsertRequest(int request_id,
                                            PendingRequest* pending_request) {
   DCHECK_EQ(0u, pending_requests_.count(request_id));
   pending_requests_[request_id].reset(pending_request);
 }
 
 linked_ptr<PendingRequest> ExtensionRequestSender::RemoveRequest(
     int request_id) {
   PendingRequestMap::iterator i = pending_requests_.find(request_id);
   if (i == pending_requests_.end())
     return linked_ptr<PendingRequest>();
   linked_ptr<PendingRequest> result = i->second;
   pending_requests_.erase(i);
   return result;
 }
 
-void ExtensionRequestSender::StartRequest(
-    const std::string& name,
-    int request_id,
-    bool has_callback,
-    bool for_io_thread,
-    base::ListValue* value_args) {
+int ExtensionRequestSender::StartRequest(const std::string& name,
+                                         bool has_callback,
+                                         bool for_io_thread,
+                                         base::ListValue* value_args) {
   ChromeV8Context* current_context = context_set_->GetCurrent();
   if (!current_context)
-    return;
+    return -1;
 
   // Get the current RenderView so that we can send a routed IPC message from
   // the correct source.
   content::RenderView* renderview = current_context->GetRenderView();
   if (!renderview)
-    return;
+    return -1;
 
   const std::set<std::string>& function_names =
       extension_dispatcher_->function_names();
   if (function_names.find(name) == function_names.end()) {
     NOTREACHED() << "Unexpected function " << name <<
         ". Did you remember to register it with ExtensionFunctionRegistry?";
-    return;
+    return -1;
   }
 
   // TODO(koz): See if we can make this a CHECK.
   if (!extension_dispatcher_->CheckCurrentContextAccessToExtensionAPI(name))
-    return;
+    return -1;
 
   GURL source_url;
   WebKit::WebSecurityOrigin source_origin;
   WebKit::WebFrame* webframe = current_context->web_frame();
   if (webframe) {
     source_url = webframe->document().url();
     source_origin = webframe->document().securityOrigin();
   }
 
   v8::Persistent<v8::Context> v8_context =
       v8::Persistent<v8::Context>::New(v8::Context::GetCurrent());
   DCHECK(!v8_context.IsEmpty());
 
+  int request_id = next_request_id_++;
+
   std::string extension_id = current_context->GetExtensionID();
-  InsertRequest(request_id, new PendingRequest(
-      v8_context, name, extension_id));
+  InsertRequest(request_id, new PendingRequest(v8_context, name, extension_id));
 
   ExtensionHostMsg_Request_Params params;
   params.name = name;
   params.arguments.Swap(value_args);
   params.extension_id = extension_id;
   params.source_url = source_url;
   params.source_origin = source_origin.toString();
   params.request_id = request_id;
   params.has_callback = has_callback;
   params.user_gesture =
       webframe ? webframe->isProcessingUserGesture() : false;
   if (for_io_thread) {
     renderview->Send(new ExtensionHostMsg_RequestForIOThread(
         renderview->GetRoutingID(), params));
   } else {
     renderview->Send(new ExtensionHostMsg_Request(
         renderview->GetRoutingID(), params));
   }
+
+  return request_id;
 }
 
-void ExtensionRequestSender::HandleResponse(int request_id,
-                                            bool success,
-                                            const base::ListValue& response,
-                                            const std::string& error) {
+void ExtensionRequestSender::OnExtensionResponse(
+    int request_id,
+    bool success,
+    const base::ListValue& response,
+    const std::string& error) {
   linked_ptr<PendingRequest> request = RemoveRequest(request_id);
 
   if (!request.get()) {
     // This should not be able to happen since we only remove requests when
     // they are handled.
     LOG(ERROR) << "Could not find specified request id: " << request_id;
     return;
   }
 
   ChromeV8Context* v8_context = context_set_->GetByV8Context(request->context);
@@ skipping 28 matching lines @@
                                            &retval));
   // In debug, the js will validate the callback parameters and return a
   // string if a validation error has occured.
 #ifndef NDEBUG
   if (!retval.IsEmpty() && !retval->IsUndefined()) {
     std::string error = *v8::String::AsciiValue(retval);
     DCHECK(false) << error;
   }
 #endif
 }