Minor History Code Cleanup.

Eliminate unused code in ExpireHistoryBackend::BroadcastDeleteNotifications.Add warning for autocomplete providers not implementing DeleteMatch. Rework HistoryProvider::DeleteMatch logic.InMemoryURLIndex::DoAutocomplete was public but should be private. Fix up some comments.

BUG=None
TEST=Unit tests succeed.
TBR=brettw
Review URL: http://codereview.chromium.org/8354015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@106401 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/autocomplete/history_quick_provider.h b/chrome/browser/autocomplete/history_quick_provider.h
index 82646696..b14fda4 100644
--- a/chrome/browser/autocomplete/history_quick_provider.h
+++ b/chrome/browser/autocomplete/history_quick_provider.h
@@ -37,9 +37,6 @@
 
   virtual void DeleteMatch(const AutocompleteMatch& match) OVERRIDE;
 
-  // Performs the autocomplete matching and scoring.
-  void DoAutocomplete();
-
   // Disable this provider. For unit testing purposes only. This is required
   // because this provider is closely associated with the HistoryURLProvider
   // and in order to properly test the latter the HistoryQuickProvider must
@@ -52,6 +49,9 @@
   FRIEND_TEST_ALL_PREFIXES(HistoryQuickProviderTest, Spans);
   FRIEND_TEST_ALL_PREFIXES(HistoryQuickProviderTest, Relevance);
 
+  // Performs the autocomplete matching and scoring.
+  void DoAutocomplete();
+
   // Creates an AutocompleteMatch from |history_match|. |max_match_score| gives
   // the maximum possible score for the match. |history_matches| is the full set
   // of matches to compare each match to when calculating confidence.