[Android] Upstream remaining changes to NTP UI code.

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

Index: chrome/browser/ui/webui/ntp/recently_closed_tabs_handler.cc
diff --git a/chrome/browser/ui/webui/ntp/recently_closed_tabs_handler.cc b/chrome/browser/ui/webui/ntp/recently_closed_tabs_handler.cc
index da09744e60dae6808d26eb6ed504d4edfb1ae5bf..74cc5c619026277005cc092dfd84576fa0ec75ea 100644
--- a/chrome/browser/ui/webui/ntp/recently_closed_tabs_handler.cc
+++ b/chrome/browser/ui/webui/ntp/recently_closed_tabs_handler.cc
@@ -57,6 +57,9 @@ void RecentlyClosedTabsHandler::RegisterMessages() {
   web_ui()->RegisterMessageCallback("reopenTab",
       base::Bind(&RecentlyClosedTabsHandler::HandleReopenTab,
                  base::Unretained(this)));
+  web_ui()->RegisterMessageCallback("clearRecentlyClosed",
+      base::Bind(&RecentlyClosedTabsHandler::HandleClearRecentlyClosed,
+                 base::Unretained(this)));
 }
 
 RecentlyClosedTabsHandler::~RecentlyClosedTabsHandler() {
@@ -68,13 +71,6 @@ void RecentlyClosedTabsHandler::HandleReopenTab(const ListValue* args) {
   if (!tab_restore_service_)
     return;
 
-  double index = -1.0;
-  CHECK(args->GetDouble(1, &index));
-
-  // There are actually less than 20 restore tab items displayed in the UI.
-  UMA_HISTOGRAM_ENUMERATION("NewTabPage.SessionRestore",
-                            static_cast<int>(index), 20);
-
   double session_to_restore = 0.0;
   CHECK(args->GetDouble(0, &session_to_restore));
 
@@ -95,6 +91,13 @@ void RecentlyClosedTabsHandler::HandleReopenTab(const ListValue* args) {
   SessionRestore::RestoreForeignSessionTab(web_ui()->GetWebContents(),
                                            session_tab, NEW_FOREGROUND_TAB);
 #else
+  double index = -1.0;
+  CHECK(args->GetDouble(1, &index));
+
+  // There are actually less than 20 restore tab items displayed in the UI.
+  UMA_HISTOGRAM_ENUMERATION("NewTabPage.SessionRestore",
+                            static_cast<int>(index), 20);
+
   TabRestoreServiceDelegate* delegate =
       TabRestoreServiceDelegate::FindDelegateForWebContents(
           web_ui()->GetWebContents());
@@ -110,6 +113,12 @@ void RecentlyClosedTabsHandler::HandleReopenTab(const ListValue* args) {
 #endif
 }
 
+void RecentlyClosedTabsHandler::HandleClearRecentlyClosed(
+    const ListValue* args) {
+  if (tab_restore_service_)

[newt (away), 2012/10/02 13:07:31]

Not totally sure about this.  If tab_restore_service_ is null, then perhaps we
still want to clear the recently closed entries.  But currently, this is
triggered only when the user long presses on a recently closed entry and selects
"remove", at which point tab_restore_service_ already exists.

I could do something like in HandleGetRecentlyClosedTabs to make this work when
tab_restore_service_ is null.  Thoughts?

[Evan Stade, 2012/10/02 14:42:43]

pull out an EnsureTabRestoreService function that inits (or attempts to)
tab_restore_service_

[newt (away), 2012/10/05 13:31:05]

Done.

+    tab_restore_service_->ClearEntries();
+}
+
 void RecentlyClosedTabsHandler::HandleGetRecentlyClosedTabs(
     const ListValue* args) {
   if (!tab_restore_service_) {