Replace HistoryQuickProvider protobuf-based caching with an SQLite-based database.

chrome/browser/diagnostics/sqlite_diagnostics.cc

Index: chrome/browser/diagnostics/sqlite_diagnostics.cc
===================================================================
--- chrome/browser/diagnostics/sqlite_diagnostics.cc	(revision 151481)
+++ chrome/browser/diagnostics/sqlite_diagnostics.cc	(working copy)
@@ -99,7 +99,8 @@
       "Sqlite.History.Error",
       "Sqlite.Thumbnail.Error",
       "Sqlite.Text.Error",
-      "Sqlite.Web.Error"
+      "Sqlite.Web.Error",
+      "Sqlite.HQPCache.Error"
     };
     return kHistogramNames[unique];
   }
@@ -127,6 +128,10 @@
   return new sql::DiagnosticErrorDelegate<HistogramUniquifier<4> >();
 }
 
+sql::ErrorDelegate* GetErrorHandlerForHQPCacheDb() {
+  return new sql::DiagnosticErrorDelegate<HistogramUniquifier<5> >();
+}
+
 DiagnosticTest* MakeSqliteWebDbTest() {
   return new SqliteIntegrityTest(true, ASCIIToUTF16("Web DB"),
                                  FilePath(chrome::kWebDataFilename));
@@ -152,6 +157,12 @@
                                  FilePath(chrome::kThumbnailsFilename));
 }
 
+DiagnosticTest* MakeSqliteHQPCacheDbTest() {
+  return new SqliteIntegrityTest(false,
+                                 ASCIIToUTF16("History Provider Cache DB"),
+                                 FilePath(chrome::kHQPCacheDBFilename));
+}
+
 DiagnosticTest* MakeSqliteAppCacheDbTest() {
   FilePath appcache_dir(content::kAppCacheDirname);
   FilePath appcache_db = appcache_dir.Append(appcache::kAppCacheDatabaseName);