Completed the code path from AndroidProviderService to HistoryBackend.

chrome/browser/history/history.h

Index: chrome/browser/history/history.h
diff --git a/chrome/browser/history/history.h b/chrome/browser/history/history.h
index e3a24e730cc8eeb5f9b43aed7f9dbc8c0b15f94e..c4a6ec6d61ccc5336bea290a08b69958209f6b2b 100644
--- a/chrome/browser/history/history.h
+++ b/chrome/browser/history/history.h
@@ -25,6 +25,10 @@
 #include "content/public/common/page_transition_types.h"
 #include "sql/init_status.h"
 
+#if defined(OS_ANDROID)
+#include "chrome/browser/android_provider_service.h"
+#endif
+
 class BookmarkService;
 class FilePath;
 class GURL;
@@ -607,6 +611,9 @@ class HistoryService : public CancelableRequestProvider,
 
  private:
   class BackendDelegate;
+#if defined(OS_ANDROID)
+  friend class AndroidProviderService;
+#endif
   friend class base::RefCountedThreadSafe<HistoryService>;
   friend class BackendDelegate;
   friend class FaviconService;
@@ -793,6 +800,31 @@ class HistoryService : public CancelableRequestProvider,
     return request->handle();
   }
 
+  template<typename BackendFunc,
+           class RequestType,  // Descendant of CancelableRequstBase.
+           typename ArgA,
+           typename ArgB,
+           typename ArgC,
+           typename ArgD>
+  Handle Schedule(SchedulePriority priority,
+                  BackendFunc func,  // Function to call on the HistoryBackend.
+                  CancelableRequestConsumerBase* consumer,
+                  RequestType* request,
+                  const ArgA& a,
+                  const ArgB& b,
+                  const ArgC& c,
+                  const ArgD& d) {
+    DCHECK(thread_) << "History service being called after cleanup";
+    LoadBackendIfNecessary();
+    if (consumer)
+      AddRequest(request, consumer);
+    ScheduleTask(priority,
+                 base::Bind(func, history_backend_.get(),
+                                   scoped_refptr<RequestType>(request),
+                                   a, b, c, d));
+    return request->handle();
+  }
+
   // ScheduleAndForget ---------------------------------------------------------
   //
   // Functions for scheduling operations on the history thread that do not need
@@ -853,6 +885,79 @@ class HistoryService : public CancelableRequestProvider,
                                       a, b, c, d));
   }
 
+#if defined(OS_ANDROID)

[sky, 2012/04/25 15:57:25]

Why do any of these methods need to be here? If you're going to make
AndroidProviderService a friend, it can invoke Schedule directly.

[michaelbai, 2012/04/26 05:32:48]

I followed the pattern of the FaviconService, if you think this is redundant, I
could move them to the service class.

Or, I could move the implementation to history_android.cc

On 2012/04/25 15:57:25, sky wrote:

[sky, 2012/04/27 21:37:22]

I would rather put them in AndroidHistoryProviderService.

+  // Android Provider ---------------------------------------------------------
+  //
+  // These Android provider related methods are exposed to the
+  // AndroidProviderService. Instead of calling these methods directly you
+  // should call the respective method on the AndroidProviderService.
+
+  // Used by the AndroidProviderService to add the history and the bookmarks.
+  void InsertHistoryAndBookmark(
+      AndroidProviderService::InsertRequest* request,
+      const history::HistoryAndBookmarkRow& row);
+
+  // Used by the AndroidProviderService to query the history and the bookmarks.
+  void QueryHistoryAndBookmarks(
+      AndroidProviderService::QueryRequest* request,
+      const std::vector<history::HistoryAndBookmarkRow::ColumnID>& projections,
+      const std::string& selection,
+      const std::vector<string16>& selection_args,
+      const std::string& sort_order);
+
+  // Used by the AndroidProviderService to update the history and the bookmarks.
+  void UpdateHistoryAndBookmarks(
+      AndroidProviderService::UpdateRequest* request,
+      const history::HistoryAndBookmarkRow& row,
+      const std::string& selection,
+      const std::vector<string16>& selection_args);
+
+  // Used by the AndroidProviderService to delete the history and the bookmarks.
+  void DeleteHistoryAndBookmarks(
+      AndroidProviderService::DeleteRequest* request,
+      const std::string& selection,
+      const std::vector<string16>& selection_args);
+
+  // Used by the AndroidProviderService to delete the history.
+  void DeleteHistory(AndroidProviderService::DeleteRequest* request,
+                     const std::string& selection,
+                     const std::vector<string16>& selection_args);
+
+  // Used by the AndroidProviderService to move the given |statement|'s current
+  // row to |destination|.
+  void MoveStatement(AndroidProviderService::MoveStatementRequest* request,
+                     history::AndroidStatement* statement,
+                     int current_pos,
+                     int destination);
+
+  // Used by the AndroidProviderService to close the statement in db thread.
+  void CloseStatement(history::AndroidStatement* statement);
+
+  // Used by the AndroidProviderService to add the search term.
+  void InsertSearchTerm(AndroidProviderService::InsertRequest* request,
+                        const history::SearchRow& row);
+
+  // Used by the AndroidProviderService to update the search terms.
+  void UpdateSearchTerms(AndroidProviderService::UpdateRequest* request,
+                         const history::SearchRow& row,
+                         const std::string& selection,
+                         const std::vector<string16>& selection_arg);
+
+  // Used by the AndroidProviderService to delete the search terms.
+  void DeleteSearchTerms(AndroidProviderService::DeleteRequest* request,
+    const std::string& selection,

[sky, 2012/04/25 15:57:25]

spacing is off

[michaelbai, 2012/04/26 05:32:48]

Done.

+                         const std::vector<string16>& selection_arg);
+
+  // Used by the AndroidProviderService to query the search terms.
+  void QuerySearchTerms(
+      AndroidProviderService::QueryRequest* request,
+      const std::vector<history::SearchRow::ColumnID>& projections,
+      const std::string& selection,
+      const std::vector<string16>& selection_args,
+      const std::string& sort_order);
+
+#endif  // defined(OS_ANDROID)
+
   content::NotificationRegistrar registrar_;
 
   // Some void primitives require some internal processing in the main thread