Have SearchProvider look up the omnibox start margin directly.

chrome/browser/autocomplete/search_provider.cc

Index: chrome/browser/autocomplete/search_provider.cc
diff --git a/chrome/browser/autocomplete/search_provider.cc b/chrome/browser/autocomplete/search_provider.cc
index d4245fd34e8719b14b02a9213e22a51447052195..3d562c6ad9fbb63ef82c1dbc4674f7623878c672 100644
--- a/chrome/browser/autocomplete/search_provider.cc
+++ b/chrome/browser/autocomplete/search_provider.cc
@@ -36,6 +36,10 @@
 #include "chrome/browser/search_engines/template_url_prepopulate_data.h"
 #include "chrome/browser/search_engines/template_url_service.h"
 #include "chrome/browser/search_engines/template_url_service_factory.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_finder.h"
+#include "chrome/browser/ui/browser_instant_controller.h"
+#include "chrome/browser/ui/search/instant_controller.h"
 #include "chrome/common/net/url_fixer_upper.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
@@ -250,8 +254,7 @@ SearchProvider::SearchProvider(AutocompleteProviderListener* listener,
       providers_(TemplateURLServiceFactory::GetForProfile(profile)),
       suggest_results_pending_(0),
       field_trial_triggered_(false),
-      field_trial_triggered_in_session_(false),
-      omnibox_start_margin_(-1) {
+      field_trial_triggered_in_session_(false) {
 }
 
 // static
@@ -369,10 +372,6 @@ void SearchProvider::ResetSession() {
   field_trial_triggered_in_session_ = false;
 }
 
-void SearchProvider::SetOmniboxStartMargin(int omnibox_start_margin) {
-  omnibox_start_margin_ = omnibox_start_margin;
-}
-
 SearchProvider::~SearchProvider() {
 }
 
@@ -1382,11 +1381,24 @@ void SearchProvider::AddMatchToMap(const string16& query_string,
                                    int accepted_suggestion,
                                    bool is_keyword,
                                    MatchMap* map) {
+  int omnibox_start_margin = chrome::kDisableStartMargin;
+  #if !defined(OS_ANDROID)

[samarth, 2013/08/07 16:19:07]

nit: don't indent this line or the #endif.

[samarth, 2013/08/07 16:19:07]

Do you need this because browser finder doesn't exist on Android? FWIW, we don't
do any of this margin shenanigans on IOS either so you may want to exclude that
as well. Please also add a comment here.

[jeremycho, 2013/08/07 22:16:05]

Done.

[jeremycho, 2013/08/07 22:16:05]

Yeah, done.

+  if (chrome::IsInstantExtendedAPIEnabled()) {
+    Browser* browser =
+        chrome::FindBrowserWithProfile(profile_, chrome::GetActiveDesktop());
+    if (browser && browser->instant_controller() &&
+        browser->instant_controller()->instant()) {
+      omnibox_start_margin =
+          browser->instant_controller()->instant()->omnibox_bounds().x();
+    }
+  }
+  #endif   // !defined(OS_ANDROID)
+
   const TemplateURL* template_url = is_keyword ?
       providers_.GetKeywordProviderURL() : providers_.GetDefaultProviderURL();
   AutocompleteMatch match = CreateSearchSuggestion(this, relevance, type,
       template_url, query_string, input_text, input_, is_keyword,
-      accepted_suggestion, omnibox_start_margin_,
+      accepted_suggestion, omnibox_start_margin,
       !is_keyword || providers_.default_provider().empty());
   if (!match.destination_url.is_valid())
     return;