Move instant support to SearchTabHelper. Fix InstantTab reset.

chrome/browser/ui/search/search_tab_helper.cc

Index: chrome/browser/ui/search/search_tab_helper.cc
diff --git a/chrome/browser/ui/search/search_tab_helper.cc b/chrome/browser/ui/search/search_tab_helper.cc
index 400a1b4af157d86e731e3e683dbda975fb99e052..74a1acdb5fe3068e06ace9a68736b05fa921bfa6 100644
--- a/chrome/browser/ui/search/search_tab_helper.cc
+++ b/chrome/browser/ui/search/search_tab_helper.cc
@@ -33,13 +33,14 @@ bool IsSearchResults(const content::WebContents* contents) {
 }  // namespace
 
 SearchTabHelper::SearchTabHelper(content::WebContents* web_contents)
-    : WebContentsObserver(web_contents),
-      is_search_enabled_(chrome::IsInstantExtendedAPIEnabled()),
+    : is_search_enabled_(chrome::IsInstantExtendedAPIEnabled()),
       user_input_in_progress_(false),
       web_contents_(web_contents) {
   if (!is_search_enabled_)
     return;
 
+  WebContentsObserver::Observe(web_contents);
+
   registrar_.Add(
       this,
       content::NOTIFICATION_NAV_ENTRY_COMMITTED,
@@ -84,11 +85,22 @@ bool SearchTabHelper::OnMessageReceived(const IPC::Message& message) {
                         OnSearchBoxShowBars)
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_SearchBoxHideBars,
                         OnSearchBoxHideBars)
+    IPC_MESSAGE_HANDLER(ChromeViewHostMsg_InstantSupportDetermined,
+                        OnInstantSupportDetermined);
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
+void SearchTabHelper::DidFinishLoad(
+    int64 /* frame_id */,
+    const GURL& /* validated_url */,
+    bool is_main_frame,
+    content::RenderViewHost* /* render_view_host */) {
+  if (is_main_frame)
+    DetermineIfPageSupportsInstant();
+}
+
 void SearchTabHelper::UpdateMode() {
   SearchMode::Type type = SearchMode::MODE_DEFAULT;
   SearchMode::Origin origin = SearchMode::ORIGIN_DEFAULT;
@@ -104,6 +116,10 @@ void SearchTabHelper::UpdateMode() {
   model_.SetMode(SearchMode(type, origin));
 }
 
+void SearchTabHelper::DetermineIfPageSupportsInstant() {
+  Send(new ChromeViewMsg_DetermineIfPageSupportsInstant(routing_id()));
+}
+
 void SearchTabHelper::OnSearchBoxShowBars(int page_id) {
   if (web_contents()->IsActiveEntry(page_id))
     model_.SetTopBarsVisible(true);
@@ -115,3 +131,9 @@ void SearchTabHelper::OnSearchBoxHideBars(int page_id) {
     Send(new ChromeViewMsg_SearchBoxBarsHidden(routing_id()));
   }
 }
+
+void SearchTabHelper::OnInstantSupportDetermined(int page_id,
+                                                 bool supports_instant) {
+  if (web_contents()->IsActiveEntry(page_id))
+    model_.SetSupportsInstant(supports_instant);
+}