Move instant support to SearchTabHelper. Fix InstantTab reset.

chrome/browser/ui/search/instant_controller.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/search/instant_controller.h"
 
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
@@ skipping 1434 matching lines @@
 
 void InstantController::ResetInstantTab() {
   // Do not wire up the InstantTab in Incognito, to prevent it from sending data
   // to the page.
   if (!search_mode_.is_origin_default() &&
       !browser_->profile()->IsOffTheRecord()) {
     content::WebContents* active_tab = browser_->GetActiveWebContents();
     if (!instant_tab_ || active_tab != instant_tab_->contents()) {
       instant_tab_.reset(new InstantTab(this));
       instant_tab_->Init(active_tab);
-      // Update theme info for this tab.
-      browser_->UpdateThemeInfo();
-      instant_tab_->SetDisplayInstantResults(instant_enabled_);
-      instant_tab_->SetOmniboxBounds(omnibox_bounds_);
-      instant_tab_->InitializeFonts();
-      StartListeningToMostVisitedChanges();
-      instant_tab_->KeyCaptureChanged(
-          omnibox_focus_state_ == OMNIBOX_FOCUS_INVISIBLE);
+      // Note that |instant_tab_| may have gotten reset in Init() if it's
+      // already known to not support instant.
+      if (instant_tab_) {
+        // Update theme info for this tab.
+        browser_->UpdateThemeInfo();
+        instant_tab_->SetDisplayInstantResults(instant_enabled_);
+        instant_tab_->SetOmniboxBounds(omnibox_bounds_);
+        instant_tab_->InitializeFonts();
+        StartListeningToMostVisitedChanges();
+        instant_tab_->KeyCaptureChanged(
+            omnibox_focus_state_ == OMNIBOX_FOCUS_INVISIBLE);
+      }
     }
 
     // Hide the |overlay_| since we are now using |instant_tab_| instead.
-    HideOverlay();
+    if (instant_tab_)
+      HideOverlay();
   } else {
     instant_tab_.reset();
   }
 }
 
 void InstantController::HideOverlay() {
   HideInternal();
   ReloadOverlayIfStale();
 }
 
 void InstantController::HideInternal() {
   LOG_INSTANT_DEBUG_EVENT(this, "Hide");
 
   // If GetOverlayContents() returns NULL, either we're already in the desired
   // MODE_DEFAULT state, or we're in the commit path. For the latter, don't
   // change the state just yet; else we may hide the overlay unnecessarily.
   // Instead, the state will be set correctly after the commit is done.
   if (GetOverlayContents()) {
     model_.SetOverlayState(SearchMode(), 0, INSTANT_SIZE_PERCENT);
     allow_overlay_to_show_search_suggestions_ = false;
 
     // Send a message asking the overlay to clear out old results.
     overlay_->Update(string16(), 0, 0, true);
   }
 
+  // Now that the overlay is hidden, try |instant_tab_| again.
+  if (!instant_tab_)
+    ResetInstantTab();
+
   // Clear the first interaction timestamp for later use.
   first_interaction_time_ = base::Time();
 }
 
 void InstantController::ShowOverlay(int height, InstantSizeUnits units) {
   // If we are on a committed search results page, the |overlay_| is not in use.
   if (instant_tab_)
     return;
 
   LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
       "Show: height=%d units=%d", height, units));
 
   // Must have updated omnibox after the last HideOverlay() to show suggestions.
   if (!allow_overlay_to_show_search_suggestions_)
     return;
 
   // The page is trying to hide itself. Hide explicitly (i.e., don't use
   // HideOverlay()) so that it can change its mind.
   if (height == 0) {
     model_.SetOverlayState(SearchMode(), 0, INSTANT_SIZE_PERCENT);
+
+    // Now that the overlay is hidden, try |instant_tab_| again.
+    if (!instant_tab_)
+      ResetInstantTab();
+
     return;
   }
 
   // If the overlay is being shown for the first time since the user started
   // typing, record a histogram value.
   if (!first_interaction_time_.is_null() && model_.mode().is_default()) {
     base::TimeDelta delta = base::Time::Now() - first_interaction_time_;
     UMA_HISTOGRAM_TIMES("Instant.TimeToFirstShow", delta);
   }
 
@@ skipping 163 matching lines @@
     }
   }
 
   return false;
 }
 
 bool InstantController::UsingLocalPage() const {
   return (instant_tab_ && instant_tab_->IsLocal()) ||
       (!instant_tab_ && overlay_ && overlay_->IsLocal());
 }