Added prerendering to omnibox.

chrome/browser/prerender/prerender_contents.cc

Index: chrome/browser/prerender/prerender_contents.cc
diff --git a/chrome/browser/prerender/prerender_contents.cc b/chrome/browser/prerender/prerender_contents.cc
index 80572279d04f26ca85ee7ed130e590a5caaa6ff6..4778e9a5fdceb424af5486de7310444ad0ad2516 100644
--- a/chrome/browser/prerender/prerender_contents.cc
+++ b/chrome/browser/prerender/prerender_contents.cc
@@ -149,8 +149,6 @@ void PrerenderContents::StartPrerendering(
   DCHECK(profile_ != NULL);
   DCHECK(!prerendering_has_started_);
   DCHECK(prerender_contents_.get() == NULL);
-  DCHECK(source_render_view_host != NULL);
-  DCHECK(source_render_view_host->view() != NULL);
 
   prerendering_has_started_ = true;
   TabContents* new_contents = new TabContents(profile_, NULL, MSG_ROUTING_NONE,
@@ -159,26 +157,28 @@ void PrerenderContents::StartPrerendering(
   TabContentsObserver::Observe(new_contents);
   prerender_contents_->download_tab_helper()->set_delegate(this);
 
-  TabContents* source_tc =
-      source_render_view_host->delegate()->GetAsTabContents();
-  if (source_tc) {
-    // So that history merging will work, get the max page ID
-    // of the old page, and add a safety margin of 10 to it (for things
-    // such as redirects).
-    starting_page_id_ = source_tc->GetMaxPageID();
-    if (starting_page_id_ < 0)
-      starting_page_id_ = 0;
-    starting_page_id_ += kPrerenderPageIdOffset;
-    prerender_contents_->controller().set_max_restored_page_id(
-        starting_page_id_);
-
-    tab_contents_delegate_.reset(new TabContentsDelegateImpl(this));
-    new_contents->set_delegate(tab_contents_delegate_.get());
-
-    // Set the size of the new TC to that of the old TC.
-    gfx::Rect tab_bounds;
-    source_tc->view()->GetContainerBounds(&tab_bounds);
-    prerender_contents_->view()->SizeContents(tab_bounds.size());
+  if (source_render_view_host) {
+    TabContents* source_tc =
+        source_render_view_host->delegate()->GetAsTabContents();
+    if (source_tc) {
+      // So that history merging will work, get the max page ID
+      // of the old page, and add a safety margin of 10 to it (for things
+      // such as redirects).
+      starting_page_id_ = source_tc->GetMaxPageID();
+      if (starting_page_id_ < 0)
+        starting_page_id_ = 0;
+      starting_page_id_ += kPrerenderPageIdOffset;
+      prerender_contents_->controller().set_max_restored_page_id(
+          starting_page_id_);
+
+      tab_contents_delegate_.reset(new TabContentsDelegateImpl(this));
+      new_contents->set_delegate(tab_contents_delegate_.get());
+
+      // Set the size of the new TC to that of the old TC.
+      gfx::Rect tab_bounds;
+      source_tc->view()->GetContainerBounds(&tab_bounds);
+      prerender_contents_->view()->SizeContents(tab_bounds.size());
+    }
   }
 
   // Register as an observer of the RenderViewHost so we get messages.