Refactor extension event distribution to use Values instead of JSON strings.

chrome/browser/extensions/api/web_navigation/web_navigation_api_helpers.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.
 
 // Implements the Chrome Extensions WebNavigation API.
 
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api_helpers.h"
 
 #include "base/json/json_writer.h"
 #include "base/string_number_conversions.h"
@@ skipping 18 matching lines @@
 namespace {
 
 // Returns |time| as milliseconds since the epoch.
 double MilliSecondsFromTime(const base::Time& time) {
   return 1000 * time.ToDoubleT();
 }
 
 // Dispatches events to the extension message service.
 void DispatchEvent(content::BrowserContext* browser_context,
                    const char* event_name,
-                   const ListValue& args,
+                   scoped_ptr<ListValue> args,
                    const GURL& url) {
-  std::string json_args;
-  base::JSONWriter::Write(&args, &json_args);
-
   EventFilteringInfo info;
   info.SetURL(url);
 
   Profile* profile = Profile::FromBrowserContext(browser_context);
   if (profile && profile->GetExtensionEventRouter()) {
     profile->GetExtensionEventRouter()->DispatchEventToRenderers(
-        event_name, json_args, profile, GURL(), info);
+        event_name, args.Pass(), profile, GURL(), info);
   }
 }
 
 }  // namespace
 
 int GetFrameId(bool is_main_frame, int64 frame_id) {
   return is_main_frame ? 0 : static_cast<int>(frame_id);
 }
 
 // Constructs and dispatches an onBeforeNavigate event.
 void DispatchOnBeforeNavigate(content::WebContents* web_contents,
                               int render_process_id,
                               int64 frame_id,
                               bool is_main_frame,
                               const GURL& validated_url) {
-  ListValue args;
+  scoped_ptr<ListValue> args(new ListValue());
   DictionaryValue* dict = new DictionaryValue();
   dict->SetInteger(keys::kTabIdKey, ExtensionTabUtil::GetTabId(web_contents));
   dict->SetString(keys::kUrlKey, validated_url.spec());
   dict->SetInteger(keys::kProcessIdKey, render_process_id);
   dict->SetInteger(keys::kFrameIdKey, GetFrameId(is_main_frame, frame_id));
   dict->SetDouble(keys::kTimeStampKey, MilliSecondsFromTime(base::Time::Now()));
-  args.Append(dict);
+  args->Append(dict);
 
   DispatchEvent(web_contents->GetBrowserContext(),
                 keys::kOnBeforeNavigate,
-                args,
+                args.Pass(),
                 validated_url);
 }
 
 // Constructs and dispatches an onCommitted or onReferenceFragmentUpdated
 // event.
 void DispatchOnCommitted(const char* event_name,
                          content::WebContents* web_contents,
                          int64 frame_id,
                          bool is_main_frame,
                          const GURL& url,
                          content::PageTransition transition_type) {
-  ListValue args;
+  scoped_ptr<ListValue> args(new ListValue());
   DictionaryValue* dict = new DictionaryValue();
   dict->SetInteger(keys::kTabIdKey, ExtensionTabUtil::GetTabId(web_contents));
   dict->SetString(keys::kUrlKey, url.spec());
   dict->SetInteger(keys::kProcessIdKey,
                    web_contents->GetRenderViewHost()->GetProcess()->GetID());
   dict->SetInteger(keys::kFrameIdKey, GetFrameId(is_main_frame, frame_id));
   dict->SetString(
       keys::kTransitionTypeKey,
       content::PageTransitionGetCoreTransitionString(transition_type));
   ListValue* qualifiers = new ListValue();
   if (transition_type & content::PAGE_TRANSITION_CLIENT_REDIRECT)
     qualifiers->Append(Value::CreateStringValue("client_redirect"));
   if (transition_type & content::PAGE_TRANSITION_SERVER_REDIRECT)
     qualifiers->Append(Value::CreateStringValue("server_redirect"));
   if (transition_type & content::PAGE_TRANSITION_FORWARD_BACK)
     qualifiers->Append(Value::CreateStringValue("forward_back"));
   if (transition_type & content::PAGE_TRANSITION_FROM_ADDRESS_BAR)
     qualifiers->Append(Value::CreateStringValue("from_address_bar"));
   dict->Set(keys::kTransitionQualifiersKey, qualifiers);
   dict->SetDouble(keys::kTimeStampKey, MilliSecondsFromTime(base::Time::Now()));
-  args.Append(dict);
+  args->Append(dict);
 
-  DispatchEvent(web_contents->GetBrowserContext(), event_name, args, url);
+  DispatchEvent(web_contents->GetBrowserContext(), event_name, args.Pass(),
+                url);
 }
 
 // Constructs and dispatches an onDOMContentLoaded event.
 void DispatchOnDOMContentLoaded(content::WebContents* web_contents,
                                 const GURL& url,
                                 bool is_main_frame,
                                 int64 frame_id) {
-  ListValue args;
+  scoped_ptr<ListValue> args(new ListValue());
   DictionaryValue* dict = new DictionaryValue();
   dict->SetInteger(keys::kTabIdKey,
                    ExtensionTabUtil::GetTabId(web_contents));
   dict->SetString(keys::kUrlKey, url.spec());
   dict->SetInteger(keys::kProcessIdKey,
                    web_contents->GetRenderViewHost()->GetProcess()->GetID());
   dict->SetInteger(keys::kFrameIdKey, GetFrameId(is_main_frame, frame_id));
   dict->SetDouble(keys::kTimeStampKey, MilliSecondsFromTime(base::Time::Now()));
-  args.Append(dict);
+  args->Append(dict);
 
   DispatchEvent(web_contents->GetBrowserContext(),
                 keys::kOnDOMContentLoaded,
-                args,
+                args.Pass(),
                 url);
 }
 
 // Constructs and dispatches an onCompleted event.
 void DispatchOnCompleted(content::WebContents* web_contents,
                          const GURL& url,
                          bool is_main_frame,
                          int64 frame_id) {
-  ListValue args;
+  scoped_ptr<ListValue> args(new ListValue());
   DictionaryValue* dict = new DictionaryValue();
   dict->SetInteger(keys::kTabIdKey,
                    ExtensionTabUtil::GetTabId(web_contents));
   dict->SetString(keys::kUrlKey, url.spec());
   dict->SetInteger(keys::kProcessIdKey,
                    web_contents->GetRenderViewHost()->GetProcess()->GetID());
   dict->SetInteger(keys::kFrameIdKey, GetFrameId(is_main_frame, frame_id));
   dict->SetDouble(keys::kTimeStampKey, MilliSecondsFromTime(base::Time::Now()));
-  args.Append(dict);
+  args->Append(dict);
 
-  DispatchEvent(web_contents->GetBrowserContext(), keys::kOnCompleted, args,
-                url);
+  DispatchEvent(web_contents->GetBrowserContext(), keys::kOnCompleted,
+                args.Pass(), url);
 }
 
 // Constructs and dispatches an onCreatedNavigationTarget event.
 void DispatchOnCreatedNavigationTarget(
     content::WebContents* web_contents,
     content::BrowserContext* browser_context,
     int64 source_frame_id,
     bool source_frame_is_main_frame,
     content::WebContents* target_web_contents,
     const GURL& target_url) {
   // Check that the tab is already inserted into a tab strip model. This code
   // path is exercised by ExtensionApiTest.WebNavigationRequestOpenTab.
   DCHECK(ExtensionTabUtil::GetTabById(
       ExtensionTabUtil::GetTabId(target_web_contents),
       Profile::FromBrowserContext(target_web_contents->GetBrowserContext()),
       false, NULL, NULL, NULL, NULL));
 
-  ListValue args;
+  scoped_ptr<ListValue> args(new ListValue());
   DictionaryValue* dict = new DictionaryValue();
   dict->SetInteger(keys::kSourceTabIdKey,
                    ExtensionTabUtil::GetTabId(web_contents));
   dict->SetInteger(keys::kSourceProcessIdKey,
                    web_contents->GetRenderViewHost()->GetProcess()->GetID());
   dict->SetInteger(keys::kSourceFrameIdKey,
       GetFrameId(source_frame_is_main_frame, source_frame_id));
   dict->SetString(keys::kUrlKey, target_url.possibly_invalid_spec());
   dict->SetInteger(keys::kTabIdKey,
                    ExtensionTabUtil::GetTabId(target_web_contents));
   dict->SetDouble(keys::kTimeStampKey, MilliSecondsFromTime(base::Time::Now()));
-  args.Append(dict);
+  args->Append(dict);
 
-  DispatchEvent(browser_context, keys::kOnCreatedNavigationTarget, args,
+  DispatchEvent(browser_context, keys::kOnCreatedNavigationTarget, args.Pass(),
                 target_url);
 }
 
 // Constructs and dispatches an onErrorOccurred event.
 void DispatchOnErrorOccurred(content::WebContents* web_contents,
                              int render_process_id,
                              const GURL& url,
                              int64 frame_id,
                              bool is_main_frame,
                              int error_code) {
-  ListValue args;
+  scoped_ptr<ListValue> args(new ListValue());
   DictionaryValue* dict = new DictionaryValue();
   dict->SetInteger(keys::kTabIdKey, ExtensionTabUtil::GetTabId(web_contents));
   dict->SetString(keys::kUrlKey, url.spec());
   dict->SetInteger(keys::kProcessIdKey, render_process_id);
   dict->SetInteger(keys::kFrameIdKey, GetFrameId(is_main_frame, frame_id));
   dict->SetString(keys::kErrorKey, net::ErrorToString(error_code));
   dict->SetDouble(keys::kTimeStampKey, MilliSecondsFromTime(base::Time::Now()));
-  args.Append(dict);
+  args->Append(dict);
 
   DispatchEvent(web_contents->GetBrowserContext(), keys::kOnErrorOccurred,
-                args, url);
+                args.Pass(), url);
 }
 
 // Constructs and dispatches an onTabReplaced event.
 void DispatchOnTabReplaced(
     content::WebContents* old_web_contents,
     content::BrowserContext* browser_context,
     content::WebContents* new_web_contents) {
-  ListValue args;
+  scoped_ptr<ListValue> args(new ListValue());
   DictionaryValue* dict = new DictionaryValue();
   dict->SetInteger(keys::kReplacedTabIdKey,
                    ExtensionTabUtil::GetTabId(old_web_contents));
   dict->SetInteger(keys::kTabIdKey,
                    ExtensionTabUtil::GetTabId(new_web_contents));
   dict->SetDouble(keys::kTimeStampKey, MilliSecondsFromTime(base::Time::Now()));
-  args.Append(dict);
+  args->Append(dict);
 
-  DispatchEvent(browser_context, keys::kOnTabReplaced, args, GURL());
+  DispatchEvent(browser_context, keys::kOnTabReplaced, args.Pass(), GURL());
 }
 
 }  // namespace web_navigation_api_helpers
 
 }  // namespace extensions