Add unit test for request coordiator

components/offline_pages/background/request_coordinator.h

Index: components/offline_pages/background/request_coordinator.h
diff --git a/components/offline_pages/background/request_coordinator.h b/components/offline_pages/background/request_coordinator.h
index 47991061dba95200a826cfac6abb9289ce0d0736..b25bf4bbf78887d099d7d5f87f272e208d4a15b8 100644
--- a/components/offline_pages/background/request_coordinator.h
+++ b/components/offline_pages/background/request_coordinator.h
@@ -9,22 +9,21 @@
 
 namespace offline_pages {
 
+class SavePageRequest;
+
 // Coordinates queueing and processing save page later requests.
 class RequestCoordinator {
  public:
   // Callback to report when the processing of a triggered task is complete.
   typedef base::Callback<void()> ProcessingDoneCallback;
 
-  struct SavePageRequest {
-    // TODO(dougarnett): define and consider making stand-alone.
-  };
-
   // TODO(dougarnett): How to inject Offliner factories and policy objects.
   RequestCoordinator();
 
   ~RequestCoordinator();
 
   // Queues |request| to later load and save when system conditions allow.
+  // Returns true if the page could be queued successfully.
   bool SavePageLater(const SavePageRequest& request);
 
   // Starts processing of one or more queued save page later requests.