Rebuild test history databases when starting up performance_ui_tests.

chrome/browser/history/top_sites.h

Index: chrome/browser/history/top_sites.h
diff --git a/chrome/browser/history/top_sites.h b/chrome/browser/history/top_sites.h
index 7ea4fa60f41e170d4cfd9d006c685130357b905f..2b011c50c6d81df22da9acffce16753642801540 100644
--- a/chrome/browser/history/top_sites.h
+++ b/chrome/browser/history/top_sites.h
@@ -66,6 +66,13 @@ class TopSites
                         const gfx::Image& thumbnail,
                         const ThumbnailScore& score);
 
+  // While testing the history system, we want to set the thumbnail to a piece
+  // of static memory.
+  bool SetPageThumbnailToJPEGBytes(
+      const GURL& url,
+      const base::RefCountedMemory* memory,
+      const ThumbnailScore& score);
+
   typedef base::Callback<void(const MostVisitedURLList&)>
       GetMostVisitedURLsCallback;
   typedef std::vector<GetMostVisitedURLsCallback> PendingCallbacks;
@@ -216,13 +223,13 @@ class TopSites
   // reading last known top sites from the DB.
   // Returns true if the thumbnail was set, false if the existing one is better.
   bool SetPageThumbnailNoDB(const GURL& url,
-                            const base::RefCountedBytes* thumbnail_data,
+                            const base::RefCountedMemory* thumbnail_data,
                             const ThumbnailScore& score);
 
-  // A version of SetPageThumbnail that takes RefCountedBytes as
+  // A version of SetPageThumbnail that takes RefCountedMemory as
   // returned by HistoryService.
   bool SetPageThumbnailEncoded(const GURL& url,
-                               const base::RefCountedBytes* thumbnail,
+                               const base::RefCountedMemory* thumbnail,
                                const ThumbnailScore& score);
 
   // Encodes the bitmap to bytes for storage to the db. Returns true if the
@@ -236,7 +243,7 @@ class TopSites
 
   // Add a thumbnail for an unknown url. See temp_thumbnails_map_.
   void AddTemporaryThumbnail(const GURL& url,
-                             const base::RefCountedBytes* thumbnail,
+                             const base::RefCountedMemory* thumbnail,
                              const ThumbnailScore& score);
 
   // Called by our timer. Starts the query for the most visited sites.