InstantExtended: don't preload the local NTP.

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 202 matching lines @@
   return true;
 }
 
 }  // namespace
 
 InstantController::InstantController(BrowserInstantController* browser,
                                      bool extended_enabled)
     : browser_(browser),
       extended_enabled_(extended_enabled),
       instant_enabled_(false),
-      use_local_overlay_only_(true),
+      use_local_page_only_(true),
       model_(ALLOW_THIS_IN_INITIALIZER_LIST(this)),
       last_omnibox_text_has_inline_autocompletion_(false),
       last_verbatim_(false),
       last_transition_type_(content::PAGE_TRANSITION_LINK),
       last_match_was_search_(false),
       omnibox_focus_state_(OMNIBOX_FOCUS_NONE),
       omnibox_bounds_(-1, -1, 0, 0),
       allow_overlay_to_show_search_suggestions_(false),
       ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)) {
 
@@ skipping 263 matching lines @@
     return scoped_ptr<content::WebContents>(NULL);
 
   LOG_INSTANT_DEBUG_EVENT(this, "ReleaseNTPContents");
 
   // Switch to the local NTP unless we're already using one.
   if (!ntp_ || (ShouldSwitchToLocalNTP() && !ntp_->IsLocalNTP()))
     ResetNTP(false, true);
 
   scoped_ptr<content::WebContents> ntp_contents = ntp_->ReleaseContents();
 
-  // Override the blacklist on an explicit user action.
-  ResetNTP(true, false);
+  if (!use_local_page_only_) {
+    // Don't preload the local NTP. Override the blacklist on an explicit user

[Jered, 2013/04/17 22:42:06]

How about:
// Preload a new Instant NTP for the next new tab, unless using the local NTP
which is not preloaded to conserve memory.

[Jered, 2013/04/17 22:42:06]

Update the comment to explain why the blacklist is overridden here (I can see
that's done by reading the code, but not why).

[samarth, 2013/04/17 23:28:15]

Done.

[samarth, 2013/04/17 23:28:15]

Done. How does this sound?

+    // action.
+    ResetNTP(true, false);
+  }
   return ntp_contents.Pass();
 }
 
 // TODO(tonyg): This method only fires when the omnibox bounds change. It also
 // needs to fire when the overlay bounds change (e.g.: open/close info bar).
 void InstantController::SetPopupBounds(const gfx::Rect& bounds) {
   if (!extended_enabled_ && !instant_enabled_)
     return;
 
   if (popup_bounds_ == bounds)
@@ skipping 361 matching lines @@
 void InstantController::TabDeactivated(content::WebContents* contents) {
   LOG_INSTANT_DEBUG_EVENT(this, "TabDeactivated");
   if (extended_enabled_ && !contents->IsBeingDestroyed())
     CommitIfPossible(INSTANT_COMMIT_FOCUS_LOST);
 
   if (GetOverlayContents())
     HideOverlay();
 }
 
 void InstantController::SetInstantEnabled(bool instant_enabled,
-                                          bool use_local_overlay_only) {
+                                          bool use_local_page_only) {
   LOG_INSTANT_DEBUG_EVENT(this, base::StringPrintf(
-      "SetInstantEnabled: instant_enabled=%d, use_local_overlay_only=%d",
-      instant_enabled, use_local_overlay_only));
+      "SetInstantEnabled: instant_enabled=%d, use_local_page_only=%d",
+      instant_enabled, use_local_page_only));
 
-  // Non extended mode does not care about |use_local_overlay_only|.
+  // Non extended mode does not care about |use_local_page_only|.
   if (instant_enabled == instant_enabled_ &&
       (!extended_enabled_ ||
-       use_local_overlay_only == use_local_overlay_only_)) {
+       use_local_page_only == use_local_page_only_)) {
     return;
   }
 
   instant_enabled_ = instant_enabled;
-  use_local_overlay_only_ = use_local_overlay_only;
+  use_local_page_only_ = use_local_page_only;
   HideInternal();
   overlay_.reset();
   if (extended_enabled_ || instant_enabled_)
     EnsureOverlayIsCurrent(false);
-  if (extended_enabled_)
-    ResetNTP(false, false);
+  if (extended_enabled_) {
+    // Preload the Instant NTP unless we are using the local NTP.

[Jered, 2013/04/17 22:42:06]

Why not? Why do we want to reset it otherwise?

[samarth, 2013/04/17 23:28:15]

Done.

+    if (use_local_page_only_)
+      ntp_.reset();
+    else
+      ResetNTP(false, false);
+  }
   if (instant_tab_)
     instant_tab_->SetDisplayInstantResults(instant_enabled_);
 }
 
 void InstantController::ThemeChanged(const ThemeBackgroundInfo& theme_info) {
   if (!extended_enabled_)
     return;
 
   if (overlay_)
     overlay_->SendThemeBackgroundInfo(theme_info);
@@ skipping 522 matching lines @@
   DCHECK_LE(0, intersection.x());
   DCHECK_LE(0, intersection.width());
   DCHECK_LE(0, intersection.height());
 
   overlay_->SetPopupBounds(intersection);
 }
 
 bool InstantController::GetInstantURL(Profile* profile,
                                       bool ignore_blacklist,
                                       std::string* instant_url) const {
-  if (extended_enabled_ && use_local_overlay_only_)
+  if (extended_enabled_ && use_local_page_only_)
     return false;
 
   const GURL instant_url_obj = chrome::GetInstantURL(profile,
                                                      omnibox_bounds_.x());
   if (!instant_url_obj.is_valid())
     return false;
 
   *instant_url = instant_url_obj.spec();
 
   if (!ignore_blacklist) {
@@ skipping 177 matching lines @@
     return false;
 
   // If this is not window startup, switch.
   // TODO(shishir): This is not completely reliable. Find a better way to detect
   // startup time.
   if (browser_->GetActiveWebContents())
     return true;
 
   return chrome::IsAggressiveLocalNTPFallbackEnabled();
 }