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

chrome/browser/diagnostics/sqlite_diagnostics.h

Index: chrome/browser/diagnostics/sqlite_diagnostics.h
===================================================================
--- chrome/browser/diagnostics/sqlite_diagnostics.h	(revision 151481)
+++ chrome/browser/diagnostics/sqlite_diagnostics.h	(working copy)
@@ -18,6 +18,7 @@
 sql::ErrorDelegate* GetErrorHandlerForThumbnailDb();
 sql::ErrorDelegate* GetErrorHandlerForTextDb();
 sql::ErrorDelegate* GetErrorHandlerForWebDb();
+sql::ErrorDelegate* GetErrorHandlerForHQPCacheDb();
 
 // Factories for the db integrity tests we run in diagnostic mode.
 DiagnosticTest* MakeSqliteWebDbTest();
@@ -25,6 +26,7 @@
 DiagnosticTest* MakeSqliteHistoryDbTest();
 DiagnosticTest* MakeSqliteArchivedHistoryDbTest();
 DiagnosticTest* MakeSqliteThumbnailsDbTest();
+DiagnosticTest* MakeSqliteHQPCacheDbTest();
 DiagnosticTest* MakeSqliteAppCacheDbTest();
 DiagnosticTest* MakeSqliteWebDatabaseTrackerDbTest();