FBTF: Move the TabRestoreService::Observer into its own file.

chrome/browser/cocoa/history_menu_bridge.mm

Index: chrome/browser/cocoa/history_menu_bridge.mm
diff --git a/chrome/browser/cocoa/history_menu_bridge.mm b/chrome/browser/cocoa/history_menu_bridge.mm
index d75043e52f316bbaa58b964a5e50064490d00397..10e1bc27f3ae5983b8a8e11cfffd33529c89c7a9 100644
--- a/chrome/browser/cocoa/history_menu_bridge.mm
+++ b/chrome/browser/cocoa/history_menu_bridge.mm
@@ -46,6 +46,23 @@ const unsigned int kRecentlyClosedCount = 10;
 
 }  // namespace
 
+HistoryMenuBridge::HistoryItem::HistoryItem()
+   : icon_requested(false),
+     menu_item(nil),
+     session_id(0) {
+}
+
+HistoryMenuBridge::HistoryItem::HistoryItem(const HistoryItem& copy)
+   : title(copy.title),
+     url(copy.url),
+     icon_requested(false),
+     menu_item(nil),
+     session_id(copy.session_id) {
+}
+
+HistoryMenuBridge::HistoryItem::~HistoryItem() {
+}
+
 HistoryMenuBridge::HistoryMenuBridge(Profile* profile)
     : controller_([[HistoryMenuCocoaController alloc] initWithBridge:this]),
       profile_(profile),