Avoid sending notifications when the bitmap data in history has not changed

chrome/browser/history/thumbnail_database.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/history/thumbnail_database.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 579 matching lines @@
                        static_cast<int>(bitmap_data->size()));
   } else {
     statement.BindNull(0);
   }
   statement.BindInt64(1, time.ToInternalValue());
   statement.BindInt64(2, bitmap_id);
 
   return statement.Run();
 }
 
+bool ThumbnailDatabase::SetFaviconBitmapLastUpdateTime(
+    FaviconBitmapID bitmap_id,
+    base::Time time) {
+  DCHECK(bitmap_id);
+  sql::Statement statement(db_.GetCachedStatement(SQL_FROM_HERE,
+      "UPDATE favicon_bitmaps SET last_updated=? WHERE id=?"));
+  statement.BindInt64(0, time.ToInternalValue());
+  statement.BindInt64(1, bitmap_id);
+  return statement.Run();
+}
+
 bool ThumbnailDatabase::DeleteFaviconBitmapsForFavicon(FaviconID icon_id) {
   sql::Statement statement(db_.GetCachedStatement(SQL_FROM_HERE,
       "DELETE FROM favicon_bitmaps WHERE icon_id=?"));
   statement.BindInt64(0, icon_id);
   return statement.Run();
 }
 
 bool ThumbnailDatabase::DeleteFaviconBitmap(FaviconBitmapID bitmap_id) {
   sql::Statement statement(db_.GetCachedStatement(SQL_FROM_HERE,
       "DELETE FROM favicon_bitmaps WHERE id=?"));
@@ skipping 535 matching lines @@
     }
     parsing_errors |= !base::StringToInt(t.token(), &height);
     favicon_sizes->push_back(gfx::Size(width, height));
   }
 
   if (parsing_errors)
     favicon_sizes->clear();
 }
 
 }  // namespace history