InstantExtended: Committed NTP

chrome/browser/ui/browser_instant_controller.cc

Index: chrome/browser/ui/browser_instant_controller.cc
diff --git a/chrome/browser/ui/browser_instant_controller.cc b/chrome/browser/ui/browser_instant_controller.cc
index 7abe3aa900015a2cc93088f32a243fdf112b7983..2c840536651b3c00032831221c621b7d43f11bf9 100644
--- a/chrome/browser/ui/browser_instant_controller.cc
+++ b/chrome/browser/ui/browser_instant_controller.cc
@@ -78,6 +78,33 @@ void BrowserInstantController::RegisterUserPrefs(PrefServiceSyncable* prefs) {
                              PrefServiceSyncable::SYNCABLE_PREF);
 }
 
+bool BrowserInstantController::MaybeSwapInInstantContents(
+    const GURL& url,
+    content::WebContents* source_contents,
+    content::WebContents** target_contents) {
+  if (url != GURL(chrome::kChromeUINewTabURL))
+    return false;
+
+  scoped_ptr<content::WebContents> instant_ntp = instant_.ReleaseNTPContents();
+  if (!instant_ntp)
+    return false;
+
+  *target_contents = instant_ntp.get();
+  instant_ntp->GetController().PruneAllButActive();
+  if (source_contents) {
+    instant_ntp->GetController().CopyStateFromAndPrune(
+        &source_contents->GetController());
+    ReplaceWebContentsAt(
+        browser_->tab_strip_model()->GetIndexOfWebContents(source_contents),
+        instant_ntp.Pass());
+  } else {
+    // 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) {
   // Unsupported dispositions.
   if (disposition == NEW_BACKGROUND_TAB || disposition == NEW_WINDOW)
@@ -93,23 +120,17 @@ bool BrowserInstantController::OpenInstant(WindowOpenDisposition disposition) {
       INSTANT_COMMIT_PRESSED_ENTER : INSTANT_COMMIT_PRESSED_ALT_ENTER);
 }
 
-void BrowserInstantController::CommitInstant(content::WebContents* preview,
-                                             bool in_new_tab) {
+void BrowserInstantController::CommitInstant(
+    scoped_ptr<content::WebContents> preview,
+    bool in_new_tab) {
   if (in_new_tab) {
     // TabStripModel takes ownership of |preview|.
-    browser_->tab_strip_model()->AddWebContents(preview, -1,
+    browser_->tab_strip_model()->AddWebContents(preview.release(), -1,
         instant_.last_transition_type(), TabStripModel::ADD_ACTIVE);
   } else {
     int index = browser_->tab_strip_model()->active_index();
-    DCHECK_NE(TabStripModel::kNoTab, index);
-    content::WebContents* active_tab =
-        browser_->tab_strip_model()->GetWebContentsAt(index);
-    // TabStripModel takes ownership of |preview|.
-    browser_->tab_strip_model()->ReplaceWebContentsAt(index, preview);
-    // InstantUnloadHandler takes ownership of |active_tab|.
-    instant_unload_handler_.RunUnloadListenersOrDestroy(active_tab, index);
-
-    GURL url = preview->GetURL();
+    const GURL& url = preview->GetURL();
+    ReplaceWebContentsAt(index, preview.Pass());
     DCHECK(browser_->profile()->GetExtensionService());
     if (browser_->profile()->GetExtensionService()->IsInstalledApp(url)) {
       AppLauncherHandler::RecordAppLaunchType(
@@ -118,6 +139,21 @@ void BrowserInstantController::CommitInstant(content::WebContents* preview,
   }
 }
 
+void BrowserInstantController::ReplaceWebContentsAt(
+    int index,
+    scoped_ptr<content::WebContents> new_contents) {
+  DCHECK_NE(TabStripModel::kNoTab, index);
+  content::WebContents* old_contents =
+      browser_->tab_strip_model()->GetWebContentsAt(index);
+  // TabStripModel takes ownership of |new_contents|.
+  browser_->tab_strip_model()->ReplaceWebContentsAt(
+      index, new_contents.release());
+  // TODO(samarth): use scoped_ptr instead of comments to document ownership
+  // transfer.
+  // InstantUnloadHandler takes ownership of |old_contents|.
+  instant_unload_handler_.RunUnloadListenersOrDestroy(old_contents, index);
+}
+
 void BrowserInstantController::SetInstantSuggestion(
     const InstantSuggestion& suggestion) {
   browser_->window()->GetLocationBar()->SetInstantSuggestion(suggestion);