[NTP4] Make TilePage and CardSlider evented to simplify code and fix page switcher bug

chrome/browser/ui/webui/ntp/app_launcher_handler.cc

Index: chrome/browser/ui/webui/ntp/app_launcher_handler.cc
diff --git a/chrome/browser/ui/webui/ntp/app_launcher_handler.cc b/chrome/browser/ui/webui/ntp/app_launcher_handler.cc
index 5f3684b9afd5cb2e1e4a1e64068ed5353596e0a0..6cd16b614c6c81e1a8275d7ad4f3d2dfa25ed8f1 100644
--- a/chrome/browser/ui/webui/ntp/app_launcher_handler.cc
+++ b/chrome/browser/ui/webui/ntp/app_launcher_handler.cc
@@ -78,7 +78,8 @@ AppLauncherHandler::AppLauncherHandler(ExtensionService* extension_service)
     : extension_service_(extension_service),
       ignore_changes_(false),
       attempted_bookmark_app_install_(false),
-      has_loaded_apps_(false) {
+      has_loaded_apps_(false),
+      uninstall_from_page_(false) {
 }
 
 AppLauncherHandler::~AppLauncherHandler() {}
@@ -305,8 +306,10 @@ void AppLauncherHandler::Observe(int type,
               content::Details<UnloadedExtensionInfo>(details)->reason ==
               extension_misc::UNLOAD_REASON_UNINSTALL));
       if (app_info.get()) {
+        scoped_ptr<base::FundamentalValue> from_page(
+            Value::CreateBooleanValue(uninstall_from_page_));
         web_ui()->CallJavascriptFunction(
-            "ntp4.appRemoved", *app_info, *uninstall_value);
+            "ntp4.appRemoved", *app_info, *uninstall_value, *from_page);
       }
       break;
     }
@@ -314,7 +317,7 @@ void AppLauncherHandler::Observe(int type,
     // The promo may not load until a couple seconds after the first NTP view,
     // so we listen for the load notification and notify the NTP when ready.
     case chrome::NOTIFICATION_WEB_STORE_PROMO_LOADED:
-      // TODO(estade): try to get rid of this inefficient operation.
+      // TODO(estade): Try to get rid of this inefficient operation.
       HandleGetApps(NULL);
       break;
     case chrome::NOTIFICATION_PREF_CHANGED: {
@@ -329,7 +332,7 @@ void AppLauncherHandler::Observe(int type,
               crx_installer->profile())) {
         return;
       }
-      // Fall Through.
+      // Fall through.
     }
     case chrome::NOTIFICATION_EXTENSION_LOAD_ERROR: {
       attempted_bookmark_app_install_ = false;
@@ -620,6 +623,9 @@ void AppLauncherHandler::HandleUninstallApp(const ListValue* args) {
     AutoReset<bool> auto_reset(&ignore_changes_, true);
     ExtensionUninstallAccepted();
   } else {
+    // We don't use an AutoReset<bool> here as the uninstall dialog runs in a

[Evan Stade, 2012/01/17 19:45:29]

the uninstall dialog runs in the UI thread, same as this code. It's not
synchronous because no dialog is synchronous.

[Dan Beam, 2012/01/18 00:07:23]

Done. (removed because of following review comment change, thanks for info, btw)

+    // different thread so it's not sync.
+    uninstall_from_page_ = true;

[Evan Stade, 2012/01/17 19:45:29]

I don't see why you need this new boolean. What is wrong with checking whether
extension_id_prompting_ is empty?

[Dan Beam, 2012/01/17 21:33:09]

Done.

     GetExtensionUninstallDialog()->ConfirmUninstall(extension);
   }
 }
@@ -842,6 +848,11 @@ void AppLauncherHandler::RegisterUserPrefs(PrefService* pref_service) {
                                  PrefService::UNSYNCABLE_PREF);
 }
 
+void AppLauncherHandler::CleanupAfterUninstall() {
+  uninstall_from_page_ = false;
+  extension_id_prompting_ = "";

[Evan Stade, 2012/01/17 19:45:29]

.clear()

[Dan Beam, 2012/01/18 00:04:27]

Done.

+}
+
 // static
 void AppLauncherHandler::RecordWebStoreLaunch(bool promo_active) {
   UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppLaunchHistogram,
@@ -927,12 +938,11 @@ void AppLauncherHandler::ExtensionUninstallAccepted() {
 
   extension_service_->UninstallExtension(extension_id_prompting_,
                                          false /* external_uninstall */, NULL);
-
-  extension_id_prompting_ = "";
+  CleanupAfterUninstall();
 }
 
 void AppLauncherHandler::ExtensionUninstallCanceled() {
-  extension_id_prompting_ = "";
+  CleanupAfterUninstall();
 }
 
 void AppLauncherHandler::InstallUIProceed() {
@@ -969,7 +979,7 @@ void AppLauncherHandler::InstallUIAbort(bool user_initiated) {
   ExtensionService::RecordPermissionMessagesHistogram(
       extension, histogram_name.c_str());
 
-  ExtensionUninstallCanceled();
+  CleanupAfterUninstall();
 }
 
 ExtensionUninstallDialog* AppLauncherHandler::GetExtensionUninstallDialog() {