Prepare HistoryProvider for componentization

chrome/browser/autocomplete/autocomplete_controller.h

Index: chrome/browser/autocomplete/autocomplete_controller.h
diff --git a/chrome/browser/autocomplete/autocomplete_controller.h b/chrome/browser/autocomplete/autocomplete_controller.h
index 6ca35cbfea76809c7bc28254be0008a379a100bb..cf7c42fd5bff1932b5282f242eece2af8ef4499a 100644
--- a/chrome/browser/autocomplete/autocomplete_controller.h
+++ b/chrome/browser/autocomplete/autocomplete_controller.h
@@ -12,6 +12,7 @@
 #include "base/strings/string16.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
+#include "chrome/browser/autocomplete/chrome_autocomplete_provider_client.h"
 #include "components/omnibox/autocomplete_input.h"
 #include "components/omnibox/autocomplete_provider.h"
 #include "components/omnibox/autocomplete_provider_listener.h"
@@ -205,6 +206,9 @@ class AutocompleteController : public AutocompleteProviderListener {
 
   AutocompleteControllerDelegate* delegate_;
 
+  // The client passed to the providers.
+  scoped_ptr<ChromeAutocompleteProviderClient> provider_client_;
+
   // A list of all providers.
   Providers providers_;