Take two for http://codereview.chromium.org/131094

This time without browser_tests timeout that caused the revert.  The problem was BrowsingHistoryHandler trying to use a dom_ui_ before being attached.

Review URL: http://codereview.chromium.org/149117

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@19556 0039d316-1c4b-4281-b951-d872f2087c98

21 files changed, 219 insertions, 165 deletions

diff --git a/chrome/browser/chrome_plugin_host.cc b/chrome/browser/chrome_plugin_host.cc
index 196a24d..4772769 100644
--- a/chrome/browser/chrome_plugin_host.cc
+++ b/chrome/browser/chrome_plugin_host.cc
@@ -313,6 +313,8 @@ class ModelessHtmlDialogDelegate : public HtmlDialogUIDelegate {
   virtual bool IsDialogModal() const { return false; }
   virtual std::wstring GetDialogTitle() const { return L"Gears"; }
   virtual GURL GetDialogContentURL() const { return params_.url; }
+  virtual void GetDOMMessageHandlers(
+      std::vector<DOMMessageHandler*>* handlers) const {}
   virtual void GetDialogSize(gfx::Size* size) const {
     size->set_width(params_.width);
     size->set_height(params_.height);
diff --git a/chrome/browser/dom_ui/dom_ui.cc b/chrome/browser/dom_ui/dom_ui.cc
index 5e92c57..3a7b221 100644
--- a/chrome/browser/dom_ui/dom_ui.cc
+++ b/chrome/browser/dom_ui/dom_ui.cc
@@ -110,7 +110,10 @@ void DOMUI::ExecuteJavascript(const std::wstring& javascript) {
 ///////////////////////////////////////////////////////////////////////////////
 // DOMMessageHandler
 
-DOMMessageHandler::DOMMessageHandler(DOMUI *dom_ui) : dom_ui_(dom_ui) {
+DOMMessageHandler* DOMMessageHandler::Attach(DOMUI* dom_ui) {
+  dom_ui_ = dom_ui;
+  RegisterMessages();
+  return this;
 }
 
 // DOMMessageHandler, protected: ----------------------------------------------
diff --git a/chrome/browser/dom_ui/dom_ui.h b/chrome/browser/dom_ui/dom_ui.h
index 553ab28..f7bb0e7 100644
--- a/chrome/browser/dom_ui/dom_ui.h
+++ b/chrome/browser/dom_ui/dom_ui.h
@@ -129,9 +129,13 @@ class DOMUI {
 // host is destroyed.
 class DOMMessageHandler {
  public:
-  explicit DOMMessageHandler(DOMUI* dom_ui);
+  DOMMessageHandler() : dom_ui_(NULL) {}
   virtual ~DOMMessageHandler() {};
 
+  // Attaches |this| to |dom_ui| in order to handle messages from it.  Declared
+  // virtual so that subclasses can do special init work as soon as the dom_ui
+  // is provided.  Returns |this| for convenience.
+  virtual DOMMessageHandler* Attach(DOMUI* dom_ui);
  protected:
   // Adds "url" and "title" keys on incoming dictionary, setting title
   // as the url as a fallback on empty title.
@@ -139,13 +143,16 @@ class DOMMessageHandler {
                              std::wstring title,
                              const GURL& gurl);
 
+  // This is where subclasses specify which messages they'd like to handle.
+  virtual void RegisterMessages() = 0;
+
   // Extract an integer value from a Value.
   bool ExtractIntegerValue(const Value* value, int* out_int);
 
   // Extract a string value from a Value.
   std::wstring ExtractStringValue(const Value* value);
 
-  DOMUI* const dom_ui_;
+  DOMUI* dom_ui_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DOMMessageHandler);
diff --git a/chrome/browser/dom_ui/downloads_dom_handler.cc b/chrome/browser/dom_ui/downloads_dom_handler.cc
index b27a520..66ee916 100644
--- a/chrome/browser/dom_ui/downloads_dom_handler.cc
+++ b/chrome/browser/dom_ui/downloads_dom_handler.cc
@@ -47,10 +47,28 @@ class DownloadItemSorter : public std::binary_function<DownloadItem*,
 
 } // namespace
 
-DownloadsDOMHandler::DownloadsDOMHandler(DOMUI* dom_ui, DownloadManager* dlm)
-    : DOMMessageHandler(dom_ui),
-      search_text_(),
+DownloadsDOMHandler::DownloadsDOMHandler(DownloadManager* dlm)
+    : search_text_(),
       download_manager_(dlm) {
+  // Create our fileicon data source.
+  g_browser_process->io_thread()->message_loop()->PostTask(FROM_HERE,
+      NewRunnableMethod(&chrome_url_data_manager,
+                        &ChromeURLDataManager::AddDataSource,
+                        new FileIconSource()));
+}
+
+DownloadsDOMHandler::~DownloadsDOMHandler() {
+  ClearDownloadItems();
+  download_manager_->RemoveObserver(this);
+}
+
+// DownloadsDOMHandler, public: -----------------------------------------------
+
+void DownloadsDOMHandler::Init() {
+  download_manager_->AddObserver(this);
+}
+
+void DownloadsDOMHandler::RegisterMessages() {
   dom_ui_->RegisterMessageCallback("getDownloads",
       NewCallback(this, &DownloadsDOMHandler::HandleGetDownloads));
   dom_ui_->RegisterMessageCallback("openFile",
@@ -73,24 +91,6 @@ DownloadsDOMHandler::DownloadsDOMHandler(DOMUI* dom_ui, DownloadManager* dlm)
       NewCallback(this, &DownloadsDOMHandler::HandleCancel));
   dom_ui_->RegisterMessageCallback("clearAll",
       NewCallback(this, &DownloadsDOMHandler::HandleClearAll));
-
-
-  // Create our fileicon data source.
-  g_browser_process->io_thread()->message_loop()->PostTask(FROM_HERE,
-      NewRunnableMethod(&chrome_url_data_manager,
-                        &ChromeURLDataManager::AddDataSource,
-                        new FileIconSource()));
-}
-
-DownloadsDOMHandler::~DownloadsDOMHandler() {
-  ClearDownloadItems();
-  download_manager_->RemoveObserver(this);
-}
-
-// DownloadsDOMHandler, public: -----------------------------------------------
-
-void DownloadsDOMHandler::Init() {
-  download_manager_->AddObserver(this);
 }
 
 void DownloadsDOMHandler::OnDownloadUpdated(DownloadItem* download) {
diff --git a/chrome/browser/dom_ui/downloads_dom_handler.h b/chrome/browser/dom_ui/downloads_dom_handler.h
index 729960c..a0158c4 100644
--- a/chrome/browser/dom_ui/downloads_dom_handler.h
+++ b/chrome/browser/dom_ui/downloads_dom_handler.h
@@ -19,11 +19,14 @@ class DownloadsDOMHandler : public DOMMessageHandler,
                             public DownloadManager::Observer,
                             public DownloadItem::Observer {
  public:
-  explicit DownloadsDOMHandler(DOMUI* dom_ui, DownloadManager* dlm);
+  explicit DownloadsDOMHandler(DownloadManager* dlm);
   virtual ~DownloadsDOMHandler();
 
   void Init();
 
+  // DOMMessageHandler implementation.
+  virtual void RegisterMessages();
+
   // DownloadItem::Observer interface
   virtual void OnDownloadUpdated(DownloadItem* download);
   virtual void OnDownloadOpened(DownloadItem* download) { }
diff --git a/chrome/browser/dom_ui/downloads_ui.cc b/chrome/browser/dom_ui/downloads_ui.cc
index 6840b00..df1c21c 100644
--- a/chrome/browser/dom_ui/downloads_ui.cc
+++ b/chrome/browser/dom_ui/downloads_ui.cc
@@ -121,9 +121,9 @@ DownloadsUI::DownloadsUI(TabContents* contents) : DOMUI(contents) {
   DownloadManager* dlm = GetProfile()->GetOriginalProfile()->
       GetDownloadManager();
 
-  DownloadsDOMHandler* handler = new DownloadsDOMHandler(this, dlm);
+  DownloadsDOMHandler* handler = new DownloadsDOMHandler(dlm);
   AddMessageHandler(handler);
-  handler->Init();
+  handler->Attach(this);
 
   DownloadsUIHTMLSource* html_source = new DownloadsUIHTMLSource();
 
diff --git a/chrome/browser/dom_ui/history_ui.cc b/chrome/browser/dom_ui/history_ui.cc
index b40b6ff..1e0bd75 100644
--- a/chrome/browser/dom_ui/history_ui.cc
+++ b/chrome/browser/dom_ui/history_ui.cc
@@ -96,32 +96,38 @@ void HistoryUIHTMLSource::StartDataRequest(const std::string& path,
 // HistoryHandler
 //
 ////////////////////////////////////////////////////////////////////////////////
-BrowsingHistoryHandler::BrowsingHistoryHandler(DOMUI* dom_ui)
-    : DOMMessageHandler(dom_ui),
-      search_text_(),
+BrowsingHistoryHandler::BrowsingHistoryHandler()
+    : search_text_(),
       remover_(NULL) {
-  dom_ui_->RegisterMessageCallback("getHistory",
-      NewCallback(this, &BrowsingHistoryHandler::HandleGetHistory));
-  dom_ui_->RegisterMessageCallback("searchHistory",
-      NewCallback(this, &BrowsingHistoryHandler::HandleSearchHistory));
-  dom_ui_->RegisterMessageCallback("deleteDay",
-      NewCallback(this, &BrowsingHistoryHandler::HandleDeleteDay));
+  
+}
 
+BrowsingHistoryHandler::~BrowsingHistoryHandler() {
+  cancelable_consumer_.CancelAllRequests();
+  if (remover_.get())
+    remover_->RemoveObserver(this);
+}
+
+DOMMessageHandler* BrowsingHistoryHandler::Attach(DOMUI* dom_ui) {
   // Create our favicon data source.
   g_browser_process->io_thread()->message_loop()->PostTask(FROM_HERE,
       NewRunnableMethod(&chrome_url_data_manager,
-                        &ChromeURLDataManager::AddDataSource,
-                        new DOMUIFavIconSource(dom_ui_->GetProfile())));
+      &ChromeURLDataManager::AddDataSource,
+      new DOMUIFavIconSource(dom_ui->GetProfile())));
 
   // Get notifications when history is cleared.
   registrar_.Add(this, NotificationType::HISTORY_URLS_DELETED,
-                 Source<Profile>(dom_ui_->GetProfile()->GetOriginalProfile()));
+      Source<Profile>(dom_ui->GetProfile()->GetOriginalProfile()));
+  return DOMMessageHandler::Attach(dom_ui);
 }
 
-BrowsingHistoryHandler::~BrowsingHistoryHandler() {
-  cancelable_consumer_.CancelAllRequests();
-  if (remover_.get())
-    remover_->RemoveObserver(this);
+void BrowsingHistoryHandler::RegisterMessages() {
+  dom_ui_->RegisterMessageCallback("getHistory",
+      NewCallback(this, &BrowsingHistoryHandler::HandleGetHistory));
+  dom_ui_->RegisterMessageCallback("searchHistory",
+      NewCallback(this, &BrowsingHistoryHandler::HandleSearchHistory));
+  dom_ui_->RegisterMessageCallback("deleteDay",
+      NewCallback(this, &BrowsingHistoryHandler::HandleDeleteDay));
 }
 
 void BrowsingHistoryHandler::HandleGetHistory(const Value* value) {
@@ -356,7 +362,7 @@ void BrowsingHistoryHandler::Observe(NotificationType type,
 ////////////////////////////////////////////////////////////////////////////////
 
 HistoryUI::HistoryUI(TabContents* contents) : DOMUI(contents) {
-  AddMessageHandler(new BrowsingHistoryHandler(this));
+  AddMessageHandler((new BrowsingHistoryHandler())->Attach(this));
 
   HistoryUIHTMLSource* html_source = new HistoryUIHTMLSource();
 
diff --git a/chrome/browser/dom_ui/history_ui.h b/chrome/browser/dom_ui/history_ui.h
index f44e033..0a47120 100644
--- a/chrome/browser/dom_ui/history_ui.h
+++ b/chrome/browser/dom_ui/history_ui.h
@@ -35,9 +35,13 @@ class BrowsingHistoryHandler : public DOMMessageHandler,
                                public NotificationObserver,
                                public BrowsingDataRemover::Observer {
  public:
-  explicit BrowsingHistoryHandler(DOMUI* dom_ui_);
+  BrowsingHistoryHandler();
   virtual ~BrowsingHistoryHandler();
 
+  // DOMMessageHandler implementation.
+  virtual DOMMessageHandler* Attach(DOMUI* dom_ui);
+  virtual void RegisterMessages();
+
   // Callback for the "getHistory" message.
   void HandleGetHistory(const Value* value);
 
diff --git a/chrome/browser/dom_ui/html_dialog_ui.cc b/chrome/browser/dom_ui/html_dialog_ui.cc
index 060625d..4f7995d 100644
--- a/chrome/browser/dom_ui/html_dialog_ui.cc
+++ b/chrome/browser/dom_ui/html_dialog_ui.cc
@@ -61,11 +61,20 @@ void HtmlDialogUI::RenderViewCreated(RenderViewHost* render_view_host) {
 
   // Pass the arguments to the renderer supplied by the delegate.
   std::string dialog_args;
+  std::vector<DOMMessageHandler*> handlers;
   HtmlDialogUIDelegate** delegate = GetPropertyAccessor().GetProperty(
       tab_contents()->property_bag());
-  if (delegate)
+  if (delegate) {
     dialog_args = (*delegate)->GetDialogArgs();
+    (*delegate)->GetDOMMessageHandlers(&handlers);
+  }
+
   render_view_host->SetDOMUIProperty("dialogArguments", dialog_args);
+  for (std::vector<DOMMessageHandler*>::iterator it = handlers.begin();
+       it != handlers.end(); ++it) {
+    (*it)->Attach(this);
+    AddMessageHandler(*it);
+  }
 }
 
 void HtmlDialogUI::OnDialogClosed(const Value* content) {
diff --git a/chrome/browser/dom_ui/html_dialog_ui.h b/chrome/browser/dom_ui/html_dialog_ui.h
index 76240cd..fce8f7c 100644
--- a/chrome/browser/dom_ui/html_dialog_ui.h
+++ b/chrome/browser/dom_ui/html_dialog_ui.h
@@ -5,6 +5,8 @@
 #ifndef CHROME_BROWSER_DOM_UI_HTML_DIALOG_UI_H_
 #define CHROME_BROWSER_DOM_UI_HTML_DIALOG_UI_H_
 
+#include <vector>
+
 #include "chrome/browser/dom_ui/dom_ui.h"
 #include "chrome/common/property_bag.h"
 #include "googleurl/src/gurl.h"
@@ -25,6 +27,13 @@ class HtmlDialogUIDelegate {
    // Get the HTML file path for the content to load in the dialog.
    virtual GURL GetDialogContentURL() const = 0;
 
+   // Get DOMMessageHandler objects to handle messages from the HTML/JS page.
+   // The handlers are used to send and receive messages from the page while it
+   // is still open.  Ownership of each handler is taken over by the DOMUI
+   // hosting the page.
+   virtual void GetDOMMessageHandlers(
+       std::vector<DOMMessageHandler*>* handlers) const = 0;
+
    // Get the size of the dialog.
    virtual void GetDialogSize(gfx::Size* size) const = 0;
 
diff --git a/chrome/browser/dom_ui/new_tab_ui.cc b/chrome/browser/dom_ui/new_tab_ui.cc
index f6af1ad..71779a8 100644
--- a/chrome/browser/dom_ui/new_tab_ui.cc
+++ b/chrome/browser/dom_ui/new_tab_ui.cc
@@ -458,8 +458,12 @@ void IncognitoTabHTMLSource::StartDataRequest(const std::string& path,
 class MostVisitedHandler : public DOMMessageHandler,
                            public NotificationObserver {
  public:
-  explicit MostVisitedHandler(DOMUI* dom_ui);
-  virtual ~MostVisitedHandler();
+  MostVisitedHandler() : url_blacklist_(NULL), pinned_urls_(NULL) {}
+  virtual ~MostVisitedHandler() { }
+
+  // DOMMessageHandler override and implementation.
+  virtual DOMMessageHandler* Attach(DOMUI* dom_ui);
+  virtual void RegisterMessages();
 
   // Callback for the "getMostVisited" message.
   void HandleGetMostVisited(const Value* value);
@@ -533,33 +537,11 @@ class MostVisitedHandler : public DOMMessageHandler,
   DISALLOW_COPY_AND_ASSIGN(MostVisitedHandler);
 };
 
-MostVisitedHandler::MostVisitedHandler(DOMUI* dom_ui)
-    : DOMMessageHandler(dom_ui) {
-  // Register ourselves as the handler for the "mostvisited" message from
-  // Javascript.
-  dom_ui_->RegisterMessageCallback("getMostVisited",
-      NewCallback(this, &MostVisitedHandler::HandleGetMostVisited));
-
-  // Register ourselves for any most-visited item blacklisting.
-  dom_ui_->RegisterMessageCallback("blacklistURLFromMostVisited",
-      NewCallback(this, &MostVisitedHandler::HandleBlacklistURL));
-  dom_ui_->RegisterMessageCallback("removeURLsFromMostVisitedBlacklist",
-      NewCallback(this, &MostVisitedHandler::HandleRemoveURLsFromBlacklist));
-  dom_ui_->RegisterMessageCallback("clearMostVisitedURLsBlacklist",
-      NewCallback(this, &MostVisitedHandler::HandleClearBlacklist));
-
-  url_blacklist_ = dom_ui_->GetProfile()->GetPrefs()->
+DOMMessageHandler* MostVisitedHandler::Attach(DOMUI* dom_ui) {
+  url_blacklist_ = dom_ui->GetProfile()->GetPrefs()->
       GetMutableDictionary(prefs::kNTPMostVisitedURLsBlacklist);
-
-  // Register ourself for pinned URL messages.
-  dom_ui->RegisterMessageCallback("addPinnedURL",
-      NewCallback(this, &MostVisitedHandler::HandleAddPinnedURL));
-  dom_ui->RegisterMessageCallback("removePinnedURL",
-      NewCallback(this, &MostVisitedHandler::HandleRemovePinnedURL));
-
-  pinned_urls_ = dom_ui_->GetProfile()->GetPrefs()->
-    GetMutableDictionary(prefs::kNTPMostVisitedPinnedURLs);
-
+  pinned_urls_ = dom_ui->GetProfile()->GetPrefs()->
+      GetMutableDictionary(prefs::kNTPMostVisitedPinnedURLs);
   // Set up our sources for thumbnail and favicon data. Since we may be in
   // testing mode with no I/O thread, only add our handler when an I/O thread
   // exists. Ownership is passed to the ChromeURLDataManager.
@@ -576,10 +558,30 @@ MostVisitedHandler::MostVisitedHandler(DOMUI* dom_ui)
 
   // Get notifications when history is cleared.
   registrar_.Add(this, NotificationType::HISTORY_URLS_DELETED,
-                 Source<Profile>(dom_ui_->GetProfile()));
+      Source<Profile>(dom_ui->GetProfile()));
+
+  return DOMMessageHandler::Attach(dom_ui);
 }
 
-MostVisitedHandler::~MostVisitedHandler() {
+void MostVisitedHandler::RegisterMessages() {
+  // Register ourselves as the handler for the "mostvisited" message from
+  // Javascript.
+  dom_ui_->RegisterMessageCallback("getMostVisited",
+      NewCallback(this, &MostVisitedHandler::HandleGetMostVisited));
+
+  // Register ourselves for any most-visited item blacklisting.
+  dom_ui_->RegisterMessageCallback("blacklistURLFromMostVisited",
+      NewCallback(this, &MostVisitedHandler::HandleBlacklistURL));
+  dom_ui_->RegisterMessageCallback("removeURLsFromMostVisitedBlacklist",
+      NewCallback(this, &MostVisitedHandler::HandleRemoveURLsFromBlacklist));
+  dom_ui_->RegisterMessageCallback("clearMostVisitedURLsBlacklist",
+      NewCallback(this, &MostVisitedHandler::HandleClearBlacklist));
+
+  // Register ourself for pinned URL messages.
+  dom_ui_->RegisterMessageCallback("addPinnedURL",
+      NewCallback(this, &MostVisitedHandler::HandleAddPinnedURL));
+  dom_ui_->RegisterMessageCallback("removePinnedURL",
+      NewCallback(this, &MostVisitedHandler::HandleRemovePinnedURL));
 }
 
 void MostVisitedHandler::HandleGetMostVisited(const Value* value) {
@@ -828,9 +830,12 @@ void MostVisitedHandler::RegisterUserPrefs(PrefService* prefs) {
 class TemplateURLHandler : public DOMMessageHandler,
                            public TemplateURLModelObserver {
  public:
-  explicit TemplateURLHandler(DOMUI* dom_ui);
+  TemplateURLHandler() : DOMMessageHandler(), template_url_model_(NULL) {}
   virtual ~TemplateURLHandler();
 
+  // DOMMessageHandler implementation.
+  virtual void RegisterMessages();
+
   // Callback for the "getMostSearched" message, sent when the page requests
   // the list of available searches.
   void HandleGetMostSearched(const Value* content);
@@ -843,27 +848,23 @@ class TemplateURLHandler : public DOMMessageHandler,
   virtual void OnTemplateURLModelChanged();
 
  private:
-  DOMUI* dom_ui_;
   TemplateURLModel* template_url_model_;  // Owned by profile.
 
   DISALLOW_COPY_AND_ASSIGN(TemplateURLHandler);
 };
 
-TemplateURLHandler::TemplateURLHandler(DOMUI* dom_ui)
-    : DOMMessageHandler(dom_ui),
-      dom_ui_(dom_ui),
-      template_url_model_(NULL) {
-  dom_ui->RegisterMessageCallback("getMostSearched",
-      NewCallback(this, &TemplateURLHandler::HandleGetMostSearched));
-  dom_ui->RegisterMessageCallback("doSearch",
-      NewCallback(this, &TemplateURLHandler::HandleDoSearch));
-}
-
 TemplateURLHandler::~TemplateURLHandler() {
   if (template_url_model_)
     template_url_model_->RemoveObserver(this);
 }
 
+void TemplateURLHandler::RegisterMessages() {
+  dom_ui_->RegisterMessageCallback("getMostSearched",
+      NewCallback(this, &TemplateURLHandler::HandleGetMostSearched));
+  dom_ui_->RegisterMessageCallback("doSearch",
+      NewCallback(this, &TemplateURLHandler::HandleDoSearch));
+}
+
 void TemplateURLHandler::HandleGetMostSearched(const Value* content) {
   // The page Javascript has requested the list of keyword searches.
   // Start loading them from the template URL backend.
@@ -989,8 +990,11 @@ void TemplateURLHandler::OnTemplateURLModelChanged() {
 class RecentlyBookmarkedHandler : public DOMMessageHandler,
                                   public BookmarkModelObserver {
  public:
-  explicit RecentlyBookmarkedHandler(DOMUI* dom_ui);
-  ~RecentlyBookmarkedHandler();
+  RecentlyBookmarkedHandler() : model_(NULL) {}
+  virtual ~RecentlyBookmarkedHandler();
+
+  // DOMMessageHandler implementation.
+  virtual void RegisterMessages();  
 
   // Callback which navigates to the bookmarks page.
   void HandleShowBookmarkPage(const Value*);
@@ -1024,27 +1028,23 @@ class RecentlyBookmarkedHandler : public DOMMessageHandler,
   virtual void BookmarkNodeFavIconLoaded(BookmarkModel* model,
                                          const BookmarkNode* node) {}
 
-  DOMUI* dom_ui_;
   // The model we're getting bookmarks from. The model is owned by the Profile.
   BookmarkModel* model_;
 
   DISALLOW_COPY_AND_ASSIGN(RecentlyBookmarkedHandler);
 };
 
-RecentlyBookmarkedHandler::RecentlyBookmarkedHandler(DOMUI* dom_ui)
-    : DOMMessageHandler(dom_ui),
-      dom_ui_(dom_ui),
-      model_(NULL) {
-  dom_ui->RegisterMessageCallback("getRecentlyBookmarked",
-      NewCallback(this,
-                  &RecentlyBookmarkedHandler::HandleGetRecentlyBookmarked));
-}
-
 RecentlyBookmarkedHandler::~RecentlyBookmarkedHandler() {
   if (model_)
     model_->RemoveObserver(this);
 }
 
+void RecentlyBookmarkedHandler::RegisterMessages() {
+  dom_ui_->RegisterMessageCallback("getRecentlyBookmarked",
+      NewCallback(this,
+                  &RecentlyBookmarkedHandler::HandleGetRecentlyBookmarked));
+}
+
 void RecentlyBookmarkedHandler::HandleGetRecentlyBookmarked(const Value*) {
   if (!model_) {
     model_ = dom_ui_->GetProfile()->GetBookmarkModel();
@@ -1100,9 +1100,12 @@ void RecentlyBookmarkedHandler::BookmarkNodeChanged(BookmarkModel* model,
 class RecentlyClosedTabsHandler : public DOMMessageHandler,
                                   public TabRestoreService::Observer {
  public:
-  explicit RecentlyClosedTabsHandler(DOMUI* dom_ui);
+  RecentlyClosedTabsHandler() : tab_restore_service_(NULL) {}
   virtual ~RecentlyClosedTabsHandler();
 
+  // DOMMessageHandler implementation.
+  virtual void RegisterMessages();
+
   // Callback for the "reopenTab" message. Rewrites the history of the
   // currently displayed tab to be the one in TabRestoreService with a
   // history of a session passed in through the content pointer.
@@ -1131,22 +1134,17 @@ class RecentlyClosedTabsHandler : public DOMMessageHandler,
   bool WindowToValue(const TabRestoreService::Window& window,
                      DictionaryValue* dictionary);
 
-  DOMUI* dom_ui_;
-
   // TabRestoreService that we are observing.
   TabRestoreService* tab_restore_service_;
 
   DISALLOW_COPY_AND_ASSIGN(RecentlyClosedTabsHandler);
 };
 
-RecentlyClosedTabsHandler::RecentlyClosedTabsHandler(DOMUI* dom_ui)
-    : DOMMessageHandler(dom_ui),
-      dom_ui_(dom_ui),
-      tab_restore_service_(NULL) {
-  dom_ui->RegisterMessageCallback("getRecentlyClosedTabs",
+void RecentlyClosedTabsHandler::RegisterMessages() {
+  dom_ui_->RegisterMessageCallback("getRecentlyClosedTabs",
       NewCallback(this,
                   &RecentlyClosedTabsHandler::HandleGetRecentlyClosedTabs));
-  dom_ui->RegisterMessageCallback("reopenTab",
+  dom_ui_->RegisterMessageCallback("reopenTab",
       NewCallback(this, &RecentlyClosedTabsHandler::HandleReopenTab));
 }
 
@@ -1286,21 +1284,22 @@ bool RecentlyClosedTabsHandler::WindowToValue(
 
 class HistoryHandler : public DOMMessageHandler {
  public:
-  explicit HistoryHandler(DOMUI* dom_ui);
+  HistoryHandler() {}
+  virtual ~HistoryHandler() {}
+
+  // DOMMessageHandler implementation.
+  virtual void RegisterMessages();
 
   // Callback which navigates to the history page and performs a search.
   void HandleSearchHistoryPage(const Value* content);
 
  private:
-  DOMUI* dom_ui_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryHandler);
 };
 
-HistoryHandler::HistoryHandler(DOMUI* dom_ui)
-    : DOMMessageHandler(dom_ui),
-      dom_ui_(dom_ui) {
-  dom_ui->RegisterMessageCallback("searchHistoryPage",
+void HistoryHandler::RegisterMessages() {
+  dom_ui_->RegisterMessageCallback("searchHistoryPage",
       NewCallback(this, &HistoryHandler::HandleSearchHistoryPage));
 }
 
@@ -1336,21 +1335,22 @@ void HistoryHandler::HandleSearchHistoryPage(const Value* content) {
 // information (treat it as RecordComputedMetrics)
 class MetricsHandler : public DOMMessageHandler {
  public:
-  explicit MetricsHandler(DOMUI* dom_ui);
-
+  MetricsHandler() {}
+  virtual ~MetricsHandler() {}
+  
+  // DOMMessageHandler implementation.
+  virtual void RegisterMessages();
+  
   // Callback which records a user action.
   void HandleMetrics(const Value* content);
 
  private:
-  DOMUI* dom_ui_;
 
   DISALLOW_COPY_AND_ASSIGN(MetricsHandler);
 };
 
-MetricsHandler::MetricsHandler(DOMUI* dom_ui)
-    : DOMMessageHandler(dom_ui),
-      dom_ui_(dom_ui) {
-  dom_ui->RegisterMessageCallback("metrics",
+void MetricsHandler::RegisterMessages() {
+  dom_ui_->RegisterMessageCallback("metrics",
       NewCallback(this, &MetricsHandler::HandleMetrics));
 }
 
@@ -1409,26 +1409,26 @@ NewTabUI::NewTabUI(TabContents* contents)
             &ChromeURLDataManager::AddDataSource,
             html_source));
   } else {
-
     if (EnableNewNewTabPage()) {
       DownloadManager* dlm = GetProfile()->GetDownloadManager();
       DownloadsDOMHandler* downloads_handler =
-          new DownloadsDOMHandler(this, dlm);
+          new DownloadsDOMHandler(dlm);
+      downloads_handler->Attach(this);
       AddMessageHandler(downloads_handler);
       downloads_handler->Init();
 
-      AddMessageHandler(new ShownSectionsHandler(this));
+      AddMessageHandler((new ShownSectionsHandler())->Attach(this));
     }
 
+    AddMessageHandler((new TemplateURLHandler())->Attach(this));
+    AddMessageHandler((new MostVisitedHandler())->Attach(this));
+    AddMessageHandler((new RecentlyBookmarkedHandler())->Attach(this));
+    AddMessageHandler((new RecentlyClosedTabsHandler())->Attach(this));
+    AddMessageHandler((new HistoryHandler())->Attach(this));
+    AddMessageHandler((new MetricsHandler())->Attach(this));
     if (EnableWebResources())
-      AddMessageHandler(new TipsHandler(this));
-
-    AddMessageHandler(new TemplateURLHandler(this));
-    AddMessageHandler(new MostVisitedHandler(this));
-    AddMessageHandler(new RecentlyBookmarkedHandler(this));
-    AddMessageHandler(new RecentlyClosedTabsHandler(this));
-    AddMessageHandler(new HistoryHandler(this));
-    AddMessageHandler(new MetricsHandler(this));
+      AddMessageHandler((new TipsHandler())->Attach(this));
+
 #ifdef CHROME_PERSONALIZATION
     if (!Personalization::IsP13NDisabled(GetProfile())) {
       AddMessageHandler(Personalization::CreateNewTabPageHandler(this));
diff --git a/chrome/browser/dom_ui/shown_sections_handler.cc b/chrome/browser/dom_ui/shown_sections_handler.cc
index 22597cb..353dae9 100644
--- a/chrome/browser/dom_ui/shown_sections_handler.cc
+++ b/chrome/browser/dom_ui/shown_sections_handler.cc
@@ -9,12 +9,10 @@
 #include "chrome/browser/profile.h"
 #include "chrome/common/pref_names.h"
 
-ShownSectionsHandler::ShownSectionsHandler(DOMUI* dom_ui)
-    : DOMMessageHandler(dom_ui),
-      dom_ui_(dom_ui) {
-  dom_ui->RegisterMessageCallback("getShownSections",
+void ShownSectionsHandler::RegisterMessages() {
+  dom_ui_->RegisterMessageCallback("getShownSections",
       NewCallback(this, &ShownSectionsHandler::HandleGetShownSections));
-  dom_ui->RegisterMessageCallback("setShownSections",
+  dom_ui_->RegisterMessageCallback("setShownSections",
       NewCallback(this, &ShownSectionsHandler::HandleSetShownSections));
 }
 
diff --git a/chrome/browser/dom_ui/shown_sections_handler.h b/chrome/browser/dom_ui/shown_sections_handler.h
index 798a14f..70a7a50 100644
--- a/chrome/browser/dom_ui/shown_sections_handler.h
+++ b/chrome/browser/dom_ui/shown_sections_handler.h
@@ -21,7 +21,11 @@ enum Section {
 
 class ShownSectionsHandler : public DOMMessageHandler {
  public:
-  explicit ShownSectionsHandler(DOMUI* dom_ui);
+  ShownSectionsHandler() {}
+  virtual ~ShownSectionsHandler() {}  
+
+  // DOMMessageHandler implementation.
+  virtual void RegisterMessages();
 
   // Callback for "getShownSections" message.
   void HandleGetShownSections(const Value* value);
@@ -32,8 +36,6 @@ class ShownSectionsHandler : public DOMMessageHandler {
   static void RegisterUserPrefs(PrefService* prefs);
 
  private:
-  DOMUI* dom_ui_;
-
   DISALLOW_COPY_AND_ASSIGN(ShownSectionsHandler);
 };
 
diff --git a/chrome/browser/dom_ui/tips_handler.cc b/chrome/browser/dom_ui/tips_handler.cc
index 3d26945..f935abd 100644
--- a/chrome/browser/dom_ui/tips_handler.cc
+++ b/chrome/browser/dom_ui/tips_handler.cc
@@ -21,14 +21,15 @@ namespace {
       L"Tips and recommendations to help you discover interesting websites.";
 }
 
-TipsHandler::TipsHandler(DOMUI* dom_ui)
-    : DOMMessageHandler(dom_ui),
-      dom_ui_(dom_ui) {
-  dom_ui->RegisterMessageCallback("getTips",
-      NewCallback(this, &TipsHandler::HandleGetTips));
-
+DOMMessageHandler* TipsHandler::Attach(DOMUI* dom_ui) {
   tips_cache_ = dom_ui_->GetProfile()->GetPrefs()->
       GetDictionary(prefs::kNTPTipsCache);
+  return DOMMessageHandler::Attach(dom_ui);  
+}
+
+void TipsHandler::RegisterMessages() {
+  dom_ui_->RegisterMessageCallback("getTips",
+      NewCallback(this, &TipsHandler::HandleGetTips));
 }
 
 void TipsHandler::HandleGetTips(const Value* content) {
diff --git a/chrome/browser/dom_ui/tips_handler.h b/chrome/browser/dom_ui/tips_handler.h
index 7847ba6..b6d5ccc 100644
--- a/chrome/browser/dom_ui/tips_handler.h
+++ b/chrome/browser/dom_ui/tips_handler.h
@@ -28,9 +28,12 @@ class Value;
 
 class TipsHandler : public DOMMessageHandler {
  public:
-  explicit TipsHandler(DOMUI* dom_ui);
+  TipsHandler() : tips_cache_(NULL) {}
+  virtual ~TipsHandler() {}
 
-  TipsHandler();
+  // DOMMessageHandler implementation and overrides. 
+  virtual DOMMessageHandler* Attach(DOMUI* dom_ui); 
+  virtual void RegisterMessages();
 
   // Callback which pulls tips data from the preferences.
   void HandleGetTips(const Value* content);
@@ -42,9 +45,6 @@ class TipsHandler : public DOMMessageHandler {
   // Make sure the string we are pushing to the NTP is a valid URL.
   bool IsValidURL(const std::wstring& url_string);
 
-  // So we can push data out to the page that has called this handler.
-  DOMUI* dom_ui_;
-
   // Filled with data from cache in preferences.
   const DictionaryValue* tips_cache_;
 
diff --git a/chrome/browser/extensions/extensions_ui.cc b/chrome/browser/extensions/extensions_ui.cc
index 6f08479..7ad40cc 100644
--- a/chrome/browser/extensions/extensions_ui.cc
+++ b/chrome/browser/extensions/extensions_ui.cc
@@ -62,9 +62,12 @@ void ExtensionsUIHTMLSource::StartDataRequest(const std::string& path,
 //
 ///////////////////////////////////////////////////////////////////////////////
 
-ExtensionsDOMHandler::ExtensionsDOMHandler(DOMUI* dom_ui,
-                                           ExtensionsService* extension_service)
-    : DOMMessageHandler(dom_ui), extensions_service_(extension_service) {
+ExtensionsDOMHandler::ExtensionsDOMHandler(
+    ExtensionsService* extension_service) 
+    : extensions_service_(extension_service) {
+ }
+
+void ExtensionsDOMHandler::RegisterMessages() {
   dom_ui_->RegisterMessageCallback("requestExtensionsData",
       NewCallback(this, &ExtensionsDOMHandler::HandleRequestExtensionsData));
   dom_ui_->RegisterMessageCallback("inspect",
@@ -257,17 +260,13 @@ ExtensionsDOMHandler::~ExtensionsDOMHandler() {
 
 // ExtensionsDOMHandler, public: -----------------------------------------------
 
-void ExtensionsDOMHandler::Init() {
-}
-
 ExtensionsUI::ExtensionsUI(TabContents* contents) : DOMUI(contents) {
   ExtensionsService *exstension_service =
       GetProfile()->GetOriginalProfile()->GetExtensionsService();
 
-  ExtensionsDOMHandler* handler = new ExtensionsDOMHandler(this,
-      exstension_service);
+  ExtensionsDOMHandler* handler = new ExtensionsDOMHandler(exstension_service);
   AddMessageHandler(handler);
-  handler->Init();
+  handler->Attach(this);
 
   ExtensionsUIHTMLSource* html_source = new ExtensionsUIHTMLSource();
 
diff --git a/chrome/browser/extensions/extensions_ui.h b/chrome/browser/extensions/extensions_ui.h
index 80e0137..38b302b 100644
--- a/chrome/browser/extensions/extensions_ui.h
+++ b/chrome/browser/extensions/extensions_ui.h
@@ -48,11 +48,11 @@ class ExtensionsUIHTMLSource : public ChromeURLDataManager::DataSource {
 // The handler for Javascript messages related to the "extensions" view.
 class ExtensionsDOMHandler : public DOMMessageHandler {
  public:
-  ExtensionsDOMHandler(DOMUI* dom_ui,
-      ExtensionsService* extension_service);
-
+  explicit ExtensionsDOMHandler(ExtensionsService* extension_service);
   virtual ~ExtensionsDOMHandler();
-  void Init();
+  
+  // DOMMessageHandler implementation.
+  virtual void RegisterMessages();
 
   // Extension Detail JSON Struct for page. (static for ease of testing).
   static DictionaryValue* CreateExtensionDetailValue(
diff --git a/chrome/browser/modal_html_dialog_delegate.h b/chrome/browser/modal_html_dialog_delegate.h
index 2ab4a9e..17c2d7d 100644
--- a/chrome/browser/modal_html_dialog_delegate.h
+++ b/chrome/browser/modal_html_dialog_delegate.h
@@ -33,6 +33,8 @@ class ModalHtmlDialogDelegate
   virtual bool IsDialogModal() const;
   virtual std::wstring GetDialogTitle() const { return L"Gears"; }
   virtual GURL GetDialogContentURL() const;
+  virtual void GetDOMMessageHandlers(
+      std::vector<DOMMessageHandler*>* handlers) const { }
   virtual void GetDialogSize(gfx::Size* size) const;
   virtual std::string GetDialogArgs() const;
   virtual void OnDialogClosed(const std::string& json_retval);
diff --git a/chrome/browser/views/html_dialog_view.cc b/chrome/browser/views/html_dialog_view.cc
index afb23ad..56c152f 100644
--- a/chrome/browser/views/html_dialog_view.cc
+++ b/chrome/browser/views/html_dialog_view.cc
@@ -93,6 +93,11 @@ GURL HtmlDialogView::GetDialogContentURL() const {
   return delegate_->GetDialogContentURL();
 }
 
+void HtmlDialogView::GetDOMMessageHandlers(
+    std::vector<DOMMessageHandler*>* handlers) const {
+  delegate_->GetDOMMessageHandlers(handlers);
+}
+
 void HtmlDialogView::GetDialogSize(gfx::Size* size) const {
   delegate_->GetDialogSize(size);
 }
diff --git a/chrome/browser/views/html_dialog_view.h b/chrome/browser/views/html_dialog_view.h
index d9edf50..ff49143 100644
--- a/chrome/browser/views/html_dialog_view.h
+++ b/chrome/browser/views/html_dialog_view.h
@@ -54,6 +54,8 @@ class HtmlDialogView
   virtual bool IsDialogModal() const;
   virtual std::wstring GetDialogTitle() const;
   virtual GURL GetDialogContentURL() const;
+  virtual void GetDOMMessageHandlers(
+      std::vector<DOMMessageHandler*>* handlers) const;
   virtual void GetDialogSize(gfx::Size* size) const;
   virtual std::string GetDialogArgs() const;
   virtual void OnDialogClosed(const std::string& json_retval);
diff --git a/chrome/common/temp_scaffolding_stubs.h b/chrome/common/temp_scaffolding_stubs.h
index 3bf3a8e..6d67947 100644
--- a/chrome/common/temp_scaffolding_stubs.h
+++ b/chrome/common/temp_scaffolding_stubs.h
@@ -332,6 +332,8 @@ class ModalHtmlDialogDelegate : public HtmlDialogUIDelegate {
    virtual bool IsDialogModal() const { return true; }
    virtual std::wstring GetDialogTitle() const { return std::wstring(); }
    virtual GURL GetDialogContentURL() const { return GURL(); }
+   virtual void GetDOMMessageHandlers(
+       std::vector<DOMMessageHandler*>* handlers) const {}
    virtual void GetDialogSize(gfx::Size* size) const {}
    virtual std::string GetDialogArgs() const { return std::string(); }
    virtual void OnDialogClosed(const std::string& json_retval) {}