Notify launcher page with onTransitionChanged event

chrome/browser/ui/app_list/app_list_view_delegate.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/browser/ui/app_list/app_list_view_delegate.h"
 
 #include <vector>
 
 #include "apps/custom_launcher_page_contents.h"
 #include "base/callback.h"
@@ skipping 435 matching lines @@
       app_list::StartPageService::Get(profile_);
   if (service) {
     service->AppListShown();
     if (service->HotwordEnabled()) {
       HotwordService* hotword_service =
           HotwordServiceFactory::GetForProfile(profile_);
       if (hotword_service)
         hotword_service->RequestHotwordSession(this);
     }
   }
+  AttachLauncherPageEventDispatcher();
+}
+
+void AppListViewDelegate::ViewReinitializedForProfileChange() {
+  AttachLauncherPageEventDispatcher();
+}
+
+void AppListViewDelegate::AttachLauncherPageEventDispatcher() {
+  std::vector<GURL> custom_launcher_page_urls;
+  GetCustomLauncherPageUrls(profile_, &custom_launcher_page_urls);
+
+  // Only the first custom launcher page gets events dispatched to it.
+  if (!custom_launcher_page_urls.empty()) {
+    chrome::HostDesktopType desktop = chrome::GetHostDesktopTypeForNativeWindow(
+        controller_->GetAppListWindow());

[tapted, 2014/11/03 00:31:20]

(overridden by later comments, but worth noting: 
GetAppListWindow can return NULL, which I guess will work here, but it's yucky.
There is AppListControllerDelegate::ForceNativeDesktop which returns a bool. You
can probably change that to return a desktop type (it's a bool to be consistent
with the app_list::AppListViewDelegate interface, which doesn't know about
chrome::DesktopType).

[calamity, 2014/11/06 02:36:31]

Acknowledged.

+    launcher_page_event_dispatcher_.reset(
+        new app_list::LauncherPageEventDispatcherViews(
+            desktop, profile_, custom_launcher_page_urls[0].host()));
+  }
 }
 
 void AppListViewDelegate::Dismiss()  {
   controller_->DismissView();
 }
 
 void AppListViewDelegate::ViewClosing() {
   controller_->ViewClosing();
 
+  launcher_page_event_dispatcher_.reset();

[tapted, 2014/11/03 00:31:20]

This lifetime is really confusing. Why can't the event dispatcher lifetime be
coupled with the WebContents?

[calamity, 2014/11/06 02:36:31]

Done.

+
   if (!profile_)
     return;
 
   app_list::StartPageService* service =
       app_list::StartPageService::Get(profile_);
   if (service) {
     service->AppListHidden();
     if (service->HotwordEnabled()) {
       HotwordService* hotword_service =
           HotwordServiceFactory::GetForProfile(profile_);
@@ skipping 220 matching lines @@
 
       // SigninManagerFactory is not a leaky singleton (unlike this class), and
       // its destructor will check that it has no remaining observers.
       scoped_observer_.RemoveAll();
       SigninManagerFactory::GetInstance()->RemoveObserver(this);
       break;
     default:
       NOTREACHED();
   }
 }