Added prerendering to omnibox.

chrome/browser/instant/instant_controller.h

Index: chrome/browser/instant/instant_controller.h
diff --git a/chrome/browser/instant/instant_controller.h b/chrome/browser/instant/instant_controller.h
index f8d4bd7475b751328aa451f3b9bc0a4892fd323b..80a2f041b8135e33406cc40fd613058f0656cfb3 100644
--- a/chrome/browser/instant/instant_controller.h
+++ b/chrome/browser/instant/instant_controller.h
@@ -193,6 +193,15 @@ class InstantController : public InstantLoaderDelegate {
  private:
   friend class InstantTest;
 
+  enum PreviewCondition {
+    PREVIEW_CONDITION_SUCCESS,
+    PREVIEW_CONDITION_INVALID_TEMPLATE_URL,
+    PREVIEW_CONDITION_JAVASCRIPT_SCHEME,
+    PREVIEW_CONDITION_EXTENSION_KEYWORD,
+    PREVIEW_CONDITION_BLACKLISTED,
+    PREVIEW_CONDITION_INSTANT_SEARCH_ONLY,
+  };
+
   typedef std::set<std::string> HostBlacklist;
 
   // Updates |displayable_loader_| and if necessary notifies the delegate.
@@ -228,10 +237,11 @@ class InstantController : public InstantLoaderDelegate {
                     bool verbatim,
                     string16* suggested_text);
 
-  // Returns true if a preview should be shown for |match|. If |match| has
-  // a TemplateURL that supports the instant API it is set in |template_url|.
-  bool ShouldShowPreviewFor(const AutocompleteMatch& match,
-                            const TemplateURL** template_url);
+  // Returns a PreviewCondition indicating why we might decide not to show a
+  // preview for |match|. If |match| has a TemplateURL that supports the instant
+  // API it is set in |template_url|.
+  PreviewCondition ShouldShowPreviewFor(const AutocompleteMatch& match,

[cbentzel, 2011/06/22 17:27:32]

Should this be named GetPreviewCondition now that it no longer returns a bool?
The "Should" prefix is usually used when a bool is returned.

[dominich, 2011/06/22 19:00:51]

Done.

+                                        const TemplateURL** template_url);
 
   // Marks the specified search engine id as not supporting instant.
   void BlacklistFromInstant(TemplateURLID id);