First pass at experimental omnibox API. There are plenty of rough edges and

chrome/browser/cocoa/location_bar_view_mac.mm

 // Copyright (c) 2010 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.
 
 #import "chrome/browser/cocoa/location_bar_view_mac.h"
 
 #include "app/l10n_util_mac.h"
 #include "app/resource_bundle.h"
 #include "base/i18n/rtl.h"
 #include "base/nsimage_cache_mac.h"
@@ skipping 237 matching lines @@
     delete fetcher;
   } else {
     // The navigation controller will delete the fetcher.
   }
 }
 
 void LocationBarViewMac::OnChangedImpl(AutocompleteTextField* field,
                                        const std::wstring& keyword,
                                        const std::wstring& short_name,
                                        const bool is_keyword_hint,
+                                       const bool is_extension_keyword,
                                        NSImage* image) {
   AutocompleteTextFieldCell* cell = [field autocompleteTextFieldCell];
   const CGFloat availableWidth([field availableDecorationWidth]);
 
   if (!keyword.empty() && !is_keyword_hint) {
     // Keyword search mode.  The text will be like "Search Engine:".
     // "Engine" is a parameter to be replaced by text based on the
     // keyword.
 
     const std::wstring min_name(CalculateMinString(short_name));
     NSString* partial_string = nil;
+    int message_id = is_extension_keyword ?
+        IDS_OMNIBOX_EXTENSION_KEYWORD_TEXT : IDS_OMNIBOX_KEYWORD_TEXT;
     if (!min_name.empty()) {
       partial_string =
-          l10n_util::GetNSStringF(IDS_OMNIBOX_KEYWORD_TEXT,
-                                  WideToUTF16(min_name));
+          l10n_util::GetNSStringF(message_id, WideToUTF16(min_name));
     }
 
     NSString* keyword_string =
-        l10n_util::GetNSStringF(IDS_OMNIBOX_KEYWORD_TEXT,
-                                WideToUTF16(short_name));
+        l10n_util::GetNSStringF(message_id, WideToUTF16(short_name));
     [cell setKeywordString:keyword_string
              partialString:partial_string
             availableWidth:availableWidth];
   } else if (!keyword.empty() && is_keyword_hint) {
     // Keyword is a hint, like "Press [Tab] to search Engine".  [Tab]
     // is a parameter to be replaced by an image.  "Engine" is a
     // parameter to be replaced by text based on the keyword.
     std::vector<size_t> content_param_offsets;
+    int message_id = is_extension_keyword ?
+        IDS_OMNIBOX_EXTENSION_KEYWORD_HINT : IDS_OMNIBOX_KEYWORD_HINT;
     const std::wstring keyword_hint(
-        l10n_util::GetStringF(IDS_OMNIBOX_KEYWORD_HINT,
+        l10n_util::GetStringF(message_id,
                               std::wstring(), short_name,
                               &content_param_offsets));
 
     // Should always be 2 offsets, see the comment in
     // location_bar_view.cc after IDS_OMNIBOX_KEYWORD_HINT fetch.
     DCHECK_EQ(content_param_offsets.size(), 2U);
 
     // Where to put the [TAB] image.
     const size_t split(content_param_offsets.front());
 
@@ skipping 13 matching lines @@
 
 void LocationBarViewMac::OnChanged() {
   // Update the location-bar icon.
   SetIcon(edit_view_->GetIcon());
 
   // Unfortunately, the unit-test Profile doesn't have the right stuff
   // setup to do what GetKeywordName() needs to do.  So do that out
   // here where we have a Profile and pass it into OnChangedImpl().
   const std::wstring keyword(edit_view_->model()->keyword());
   std::wstring short_name;
+  bool is_extension_keyword = false;
   if (!keyword.empty()) {
-    short_name = GetKeywordName(profile_, keyword);
+    short_name = profile_->GetTemplateURLModel()->
+        GetKeywordShortName(keyword, &is_extension_keyword);
   }
 
   // TODO(shess): Implementation exported to a static so that it can
   // be unit tested without having to setup the entire object.  This
   // makes me sad.  I should fix that.
   OnChangedImpl(field_,
                 keyword,
                 short_name,
                 edit_view_->model()->is_keyword_hint(),
+                is_extension_keyword,
                 GetTabButtonImage());
 }
 
 void LocationBarViewMac::OnInputInProgress(bool in_progress) {
   toolbar_model_->set_input_in_progress(in_progress);
   Update(NULL, false);
 }
 
 void LocationBarViewMac::OnSetFocus() {
   // Update the keyword and search hint states.
@@ skipping 653 matching lines @@
       ++result;
   }
   return result;
 }
 
 void LocationBarViewMac::PageActionViewList::OnMousePressed(NSRect iconFrame,
                                                             size_t index) {
   ViewAt(index)->OnMousePressed(iconFrame);
 }