Move instant support to SearchTabHelper.

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 4cbbd8aa2dfe33e1049e180d742d98c106842fdc..d191ce9c87921ce9f3d54c8b7c48d7726363a516 100644
--- a/chrome/browser/ui/search/search_tab_helper.cc
+++ b/chrome/browser/ui/search/search_tab_helper.cc
@@ -4,12 +4,17 @@
 
 #include "chrome/browser/ui/search/search_tab_helper.h"
 
+#include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/search.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/url_constants.h"
+#include "content/public/browser/navigation_controller.h"
+#include "content/public/browser/navigation_details.h"
 #include "content/public/browser/navigation_entry.h"
+#include "content/public/browser/navigation_type.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
+#include "content/public/browser/web_contents.h"
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(SearchTabHelper);
 
@@ -30,6 +35,14 @@ bool IsSearchResults(const content::WebContents* contents) {
   return !chrome::GetSearchTerms(contents).empty();
 }
 
+// TODO(kmadhusu): Move this helper from anonymous namespace to chrome
+// namespace and remove InstantPage::IsLocal().
+bool IsLocal(const content::WebContents* contents) {
+  return contents &&
+      (contents->GetURL() == GURL(chrome::kChromeSearchLocalNtpUrl) ||
+       contents->GetURL() == GURL(chrome::kChromeSearchLocalGoogleNtpUrl));
+}
+
 }  // namespace
 
 SearchTabHelper::SearchTabHelper(content::WebContents* web_contents)
@@ -42,6 +55,9 @@ SearchTabHelper::SearchTabHelper(content::WebContents* web_contents)
   if (!is_search_enabled_)
     return;
 
+  // Observe NOTIFICATION_NAV_ENTRY_COMMITTED events so we can reset state
+  // associated with the WebContents  (such as mode, last known most visited
+  // items, instant support state etc).
   registrar_.Add(
       this,
       content::NOTIFICATION_NAV_ENTRY_COMMITTED,
@@ -84,13 +100,47 @@ bool SearchTabHelper::UpdateLastKnownMostVisitedItems(
   return true;
 }
 
+void SearchTabHelper::InstantSupportChanged(bool instant_support) {
+  if (!is_search_enabled_)
+    return;
+
+  model_.SetInstantSupportState(instant_support ? INSTANT_SUPPORT_YES :
+                                                  INSTANT_SUPPORT_NO);
+}
+
+bool SearchTabHelper::SupportsInstant() const {
+  return model_.instant_support() == INSTANT_SUPPORT_YES;
+}
+
 void SearchTabHelper::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   DCHECK_EQ(content::NOTIFICATION_NAV_ENTRY_COMMITTED, type);
+  content::LoadCommittedDetails* load_details =
+      content::Details<content::LoadCommittedDetails>(details).ptr();
+  if (!load_details->is_main_frame)
+    return;
+
   UpdateMode();
   last_known_most_visited_items_.clear();
+
+  // Already determined the instant support state for this page, do not reset
+  // the instant support state.
+  //
+  // When we get a navigation entry committed event, there seem to be two ways
+  // to tell whether the navigation was "in-page". Ideally, when
+  // LoadCommittedDetails::is_in_page is true, we should have
+  // LoadCommittedDetails::type to be NAVIGATION_TYPE_IN_PAGE. Unfortunately,
+  // they are different in some cases. To workaround this bug, we are checking
+  // (is_in_page || type == NAVIGATION_TYPE_IN_PAGE). Please refer to
+  // crbug.com/251330 for more details.
+  if (load_details->is_in_page ||
+      load_details->type == content::NAVIGATION_TYPE_IN_PAGE) {
+    return;
+  }
+
+  model_.SetInstantSupportState(INSTANT_SUPPORT_UNKNOWN);
 }
 
 bool SearchTabHelper::OnMessageReceived(const IPC::Message& message) {
@@ -100,11 +150,22 @@ 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;
@@ -127,12 +188,39 @@ void SearchTabHelper::UpdateMode() {
     // OmniboxEditModel::SetInputInProgress() which is called from
     // OmniboxEditModel::Revert().
     model_.SetState(SearchModel::State(SearchMode(type, origin),
-                                       model_.state().top_bars_visible));
+                                       model_.state().top_bars_visible,
+                                       model_.instant_support()));
   } else {
     model_.SetMode(SearchMode(type, origin));
   }
 }
 
+void SearchTabHelper::DetermineIfPageSupportsInstant() {
+  Profile* profile =
+      Profile::FromBrowserContext(web_contents_->GetBrowserContext());
+  if (!chrome::ShouldAssignURLToInstantRenderer(web_contents_->GetURL(),
+                                                profile)) {
+    // The page is not in the Instant process. This page does not support
+    // instant. If we send an IPC message to a page that is not in the Instant
+    // process, it will never receive it and will never respond. Therefore,
+    // return immediately.
+    InstantSupportChanged(false);
+  } else if (IsLocal(web_contents_)) {
+    // Local pages always support Instant.
+    InstantSupportChanged(true);
+  } else {
+    Send(new ChromeViewMsg_DetermineIfPageSupportsInstant(routing_id()));
+  }
+}
+
+void SearchTabHelper::OnInstantSupportDetermined(int page_id,
+                                                 bool instant_support) {
+  if (!web_contents()->IsActiveEntry(page_id))
+    return;
+
+  InstantSupportChanged(instant_support);
+}
+
 void SearchTabHelper::OnSearchBoxShowBars(int page_id) {
   if (web_contents()->IsActiveEntry(page_id))
     model_.SetTopBarsVisible(true);