Browser: add or show some menu items in BrowserActivity

Add for carrier feature. Add homepage/back/history/exit menu items
to make browser functions more complete for user.

CRs-Fixed: 516260

Change-Id: I9d60a36e7fe5ef323aee81ae185982552f328302
diff --git a/res/menu/browser.xml b/res/menu/browser.xml
index 9d95e88..9be1208 100644
--- a/res/menu/browser.xml
+++ b/res/menu/browser.xml
@@ -17,6 +17,10 @@
 <menu xmlns:android="http://schemas.android.com/apk/res/android">
     <group
         android:id="@+id/MAIN_MENU">
+        <item
+            android:id="@+id/homepage_menu_id"
+            android:title="@string/go_home"
+            android:alphabeticShortcut="&#32;" />
         <group
             android:id="@+id/NAV_MENU"
             android:visible="@bool/menu_show_navigation">
@@ -29,6 +33,9 @@
                 android:icon="@*android:drawable/ic_menu_forward" />
         </group>
         <item
+            android:id="@+id/back_menu_id"
+            android:title="@string/back" />
+        <item
             android:id="@+id/new_tab_menu_id"
             android:title="@string/new_tab"
             android:icon="@drawable/ic_new_window_holo_dark"
@@ -94,6 +101,9 @@
             android:title="@string/menu_preferences"
             android:icon="@drawable/ic_settings_holo_dark"
             android:alphabeticShortcut="p" />
+        <item
+            android:id="@+id/exit_menu_id"
+            android:title="@string/exit" />
         <!-- followings are debug only -->
         <item
             android:id="@+id/dump_nav_menu_id"