Add IPC plumbing code for Quota API

content/common/child_thread.h

Index: content/common/child_thread.h
diff --git a/content/common/child_thread.h b/content/common/child_thread.h
index 4b27ab7968b387883ec1f69ae8e9d9e02b6b4ab5..f2ac864ade86381c86d90f91d72c22abd6852ad3 100644
--- a/content/common/child_thread.h
+++ b/content/common/child_thread.h
@@ -14,6 +14,7 @@
 class FileSystemDispatcher;
 class MessageLoop;
 class NotificationService;
+class QuotaDispatcher;
 class ResourceDispatcher;
 class SocketStreamDispatcher;
 
@@ -56,6 +57,10 @@ class ChildThread : public IPC::Channel::Listener,
     return file_system_dispatcher_.get();
   }
 
+  QuotaDispatcher* quota_dispatcher() const {
+    return quota_dispatcher_.get();
+  }
+
   // Safe to call on any thread, as long as it's guaranteed that the thread's
   // lifetime is less than the main thread.
   IPC::SyncMessageFilter* sync_message_filter();
@@ -122,6 +127,8 @@ class ChildThread : public IPC::Channel::Listener,
 
   scoped_ptr<FileSystemDispatcher> file_system_dispatcher_;
 
+  scoped_ptr<QuotaDispatcher> quota_dispatcher_;
+
   DISALLOW_COPY_AND_ASSIGN(ChildThread);
 };