Instant Extended: Fallback to local preview if the remote instant page is not ready on user input.

chrome/browser/instant/instant_controller.cc

Index: chrome/browser/instant/instant_controller.cc
diff --git a/chrome/browser/instant/instant_controller.cc b/chrome/browser/instant/instant_controller.cc
index 17a2fbae5cef7ce269772629b18ae3b34666e0b4..b94546bab03bb2920172f53274218b7e399c9bfe 100644
--- a/chrome/browser/instant/instant_controller.cc
+++ b/chrome/browser/instant/instant_controller.cc
@@ -371,6 +371,15 @@ bool InstantController::Update(const AutocompleteMatch& match,
     if (first_interaction_time_.is_null())
       first_interaction_time_ = base::Time::Now();
     allow_preview_to_show_search_suggestions_ = true;
+
+    // For extended mode, if the loader is not ready at this point, switch over
+    // to a backup loader.
+    if (extended_enabled_ && !loader_->supports_instant() &&
+        !loader_->IsUsingLocalPreview() && browser_->GetActiveWebContents()) {
+      CreateLoader(kLocalOmniboxPopupURL, browser_->GetActiveWebContents());
+      loader_->set_is_in_fallback_mode(true);
+    }
+
     loader_->Update(extended_enabled_ ? user_text : full_text,
                     selection_start, selection_end, verbatim);
   }
@@ -921,6 +930,7 @@ void InstantController::OmniboxLostFocus(gfx::NativeView view_gaining_focus) {
   // If the preview is not showing at all, recreate it if it's stale.
   if (model_.mode().is_default()) {
     OnStaleLoader();
+    MaybeSwitchToRemoteLoader();
     return;
   }
 
@@ -961,6 +971,10 @@ bool InstantController::EnsureLoaderIsCurrent() {
   if (!active_tab)
     return false;
 
+  // In fallback mode, we do not change the loader.
+  if (loader_ && loader_->is_in_fallback_mode())
+    return true;
+
   std::string instant_url;
   if (!GetInstantURL(active_tab, &instant_url)) {
     // If we are in extended mode, fallback to the local popup.
@@ -987,6 +1001,7 @@ void InstantController::CreateLoader(const std::string& instant_url,
     loader_->SearchModeChanged(search_mode_);
     loader_->KeyCaptureChanged(omnibox_focus_state_ == OMNIBOX_FOCUS_INVISIBLE);
     loader_->SetMarginSize(start_margin_, end_margin_);
+    loader_->InitializeFonts();
   }
 
   // Restart the stale loader timer.
@@ -1011,6 +1026,17 @@ void InstantController::OnStaleLoader() {
   }
 }
 
+void InstantController::MaybeSwitchToRemoteLoader() {
+  if (!loader_ || !loader_->is_in_fallback_mode() ||
+      omnibox_focus_state_ != OMNIBOX_FOCUS_NONE ||
+      !model_.mode().is_default()) {
+    return;
+  }
+
+  loader_->set_is_in_fallback_mode(false);
+  EnsureLoaderIsCurrent();
+}
+
 void InstantController::ResetInstantTab() {
   // Do not wire up the InstantTab if instant should only use local previews, to
   // prevent it from sending data to the page.
@@ -1021,6 +1047,7 @@ void InstantController::ResetInstantTab() {
       instant_tab_->Init();
       instant_tab_->SetDisplayInstantResults(instant_enabled_);
       instant_tab_->SetMarginSize(start_margin_, end_margin_);
+      instant_tab_->InitializeFonts();
     }
 
     // Hide the |loader_| since we are now using |instant_tab_| instead.
@@ -1033,6 +1060,7 @@ void InstantController::ResetInstantTab() {
 void InstantController::HideLoader() {
   HideInternal();
   OnStaleLoader();
+  MaybeSwitchToRemoteLoader();
 }
 
 void InstantController::HideInternal() {