Revert 244407 "InstantExtended: remove dead code related to the ..."

trunk/src/chrome/browser/ui/browser_instant_controller.cc

Index: trunk/src/chrome/browser/ui/browser_instant_controller.cc
===================================================================
--- trunk/src/chrome/browser/ui/browser_instant_controller.cc	(revision 244428)
+++ trunk/src/chrome/browser/ui/browser_instant_controller.cc	(working copy)
@@ -16,6 +16,7 @@
 #include "chrome/browser/ui/omnibox/location_bar.h"
 #include "chrome/browser/ui/omnibox/omnibox_popup_model.h"
 #include "chrome/browser/ui/omnibox/omnibox_view.h"
+#include "chrome/browser/ui/search/instant_ntp.h"
 #include "chrome/browser/ui/search/instant_search_prerenderer.h"
 #include "chrome/browser/ui/search/search_model.h"
 #include "chrome/browser/ui/search/search_tab_helper.h"
@@ -45,11 +46,13 @@
 
 BrowserInstantController::BrowserInstantController(Browser* browser)
     : browser_(browser),
-      instant_(this) {
+      instant_(this),
+      instant_unload_handler_(browser) {
   browser_->search_model()->AddObserver(this);
 
   InstantService* instant_service =
       InstantServiceFactory::GetForProfile(profile());
+  instant_service->OnBrowserInstantControllerCreated();
   instant_service->AddObserver(this);
 }
 
@@ -59,8 +62,64 @@
   InstantService* instant_service =
       InstantServiceFactory::GetForProfile(profile());
   instant_service->RemoveObserver(this);
+  instant_service->OnBrowserInstantControllerDestroyed();
 }
 
+bool BrowserInstantController::MaybeSwapInInstantNTPContents(
+    const GURL& url,
+    content::WebContents* source_contents,
+    content::WebContents** target_contents) {
+  if (url != GURL(chrome::kChromeUINewTabURL))
+    return false;
+
+  GURL extension_url(url);
+  if (ExtensionWebUI::HandleChromeURLOverride(&extension_url, profile())) {
+    // If there is an extension overriding the NTP do not use the Instant NTP.
+    return false;
+  }
+
+  InstantService* instant_service =
+      InstantServiceFactory::GetForProfile(profile());
+  scoped_ptr<content::WebContents> instant_ntp =
+      instant_service->ReleaseNTPContents();
+  if (!instant_ntp)
+    return false;
+
+  *target_contents = instant_ntp.get();
+  if (source_contents) {
+    // If the Instant NTP hasn't yet committed an entry, we can't call
+    // CopyStateFromAndPrune.  Instead, load the Local NTP URL directly in the
+    // source contents.
+    // TODO(sreeram): Always using the local URL is wrong in the case of the
+    // first tab in a window where we might want to use the remote URL. Fix.
+    if (!instant_ntp->GetController().CanPruneAllButLastCommitted()) {
+      source_contents->GetController().LoadURL(chrome::GetLocalInstantURL(
+          profile()), content::Referrer(), content::PAGE_TRANSITION_GENERATED,
+          std::string());
+      *target_contents = source_contents;
+    } else {
+      instant_ntp->GetController().CopyStateFromAndPrune(
+          &source_contents->GetController(), false);
+      ReplaceWebContentsAt(
+          browser_->tab_strip_model()->GetIndexOfWebContents(source_contents),
+          instant_ntp.Pass());
+    }
+  } else {
+    // If the Instant NTP hasn't yet committed an entry, we can't call
+    // PruneAllButLastCommitted.  In that case, there shouldn't be any entries
+    // to prune anyway.
+    if (instant_ntp->GetController().CanPruneAllButLastCommitted())
+      instant_ntp->GetController().PruneAllButLastCommitted();
+    else
+      CHECK(!instant_ntp->GetController().GetLastCommittedEntry());
+
+    // If |source_contents| is NULL, then the caller is responsible for
+    // inserting instant_ntp into the tabstrip and will take ownership.
+    ignore_result(instant_ntp.release());
+  }
+  return true;
+}
+
 bool BrowserInstantController::OpenInstant(WindowOpenDisposition disposition,
                                            const GURL& url) {
   // Unsupported dispositions.
@@ -97,6 +156,16 @@
   return browser_->profile();
 }
 
+void BrowserInstantController::ReplaceWebContentsAt(
+    int index,
+    scoped_ptr<content::WebContents> new_contents) {
+  DCHECK_NE(TabStripModel::kNoTab, index);
+  scoped_ptr<content::WebContents> old_contents(browser_->tab_strip_model()->
+      ReplaceWebContentsAt(index, new_contents.release()));
+  instant_unload_handler_.RunUnloadListenersOrDestroy(old_contents.Pass(),
+                                                      index);
+}
+
 content::WebContents* BrowserInstantController::GetActiveWebContents() const {
   return browser_->tab_strip_model()->GetActiveWebContents();
 }