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 89d29257b45d18355f036406f556a99ad4426500..97227058f1be644f9f97fbb7901918e2f21ef256 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"
@@ -251,7 +255,6 @@ SearchProvider::SearchProvider(AutocompleteProviderListener* listener,
       suggest_results_pending_(0),
       field_trial_triggered_(false),
       field_trial_triggered_in_session_(false),
-      omnibox_start_margin_(-1),
       prevent_search_history_inlining_(
           OmniboxFieldTrial::SearchHistoryPreventInlining()),
       disable_search_history_(
@@ -373,10 +376,6 @@ void SearchProvider::ResetSession() {
   field_trial_triggered_in_session_ = false;
 }
 
-void SearchProvider::SetOmniboxStartMargin(int omnibox_start_margin) {
-  omnibox_start_margin_ = omnibox_start_margin;
-}
-
 SearchProvider::~SearchProvider() {
 }
 
@@ -1380,11 +1379,22 @@ void SearchProvider::AddMatchToMap(const string16& query_string,
                                    int accepted_suggestion,
                                    bool is_keyword,
                                    MatchMap* map) {
+  int omnibox_start_margin = chrome::kDisableStartMargin;
+  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()->GetOmniboxBounds().x();
+    }
+  }
+
   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;