[Offline Pages] Adds UMA for result of attempts to immediately start background loading.

components/offline_pages/background/request_coordinator.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_COORDINATOR_H_
 #define COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_COORDINATOR_H_
 
 #include <memory>
 
 #include "base/callback.h"
@@ skipping 148 matching lines @@
   // the next StartProcessing() call.
   bool is_canceled() {
     return is_stopped_;
   }
 
   OfflineEventLogger* GetLogger() {
     return &event_logger_;
   }
 
  private:
+  enum class OfflinerImmediateStartStatus {

[Mark P, 2016/10/06 18:54:41]

Please follow the advice here about enum histograms:
https://chromium.googlesource.com/chromium/src.git/+/HEAD/tools/metrics/histo...

[dougarnett, 2016/10/06 23:05:00]

switched to unscoped enum with explicit values

+    STARTED,
+    BUSY,
+    NOT_ACCEPTED,
+    NO_CONNECTION,
+    NO_EFFECTIVE_CONNECTION,

[Mark P, 2016/10/06 18:54:41]

What's the difference between this one and the one above?  This probably
deserved a comment here and in the histograms.xml enum.

[dougarnett, 2016/10/06 23:05:00]

Done.

+    NOT_STARTED_ON_SVELTE,
+    // NOTE: insert new values above this line and update histogram enum too.
+    STATUS_COUNT,
+  };
+
   // Receives the results of a get from the request queue, and turns that into
   // SavePageRequest objects for the caller of GetQueuedRequests.
   void GetQueuedRequestsCallback(
       const GetRequestsCallback& callback,
       RequestQueue::GetRequestsResult result,
       std::vector<std::unique_ptr<SavePageRequest>> requests);
 
   // Receives the results of a get from the request queue, and turns that into
   // SavePageRequest objects for the caller of GetQueuedRequests.
   void GetRequestsForSchedulingCallback(
@@ skipping 19 matching lines @@
 
   void HandleRemovedRequests(
       BackgroundSavePageResult status,
       const RequestQueue::UpdateMultipleRequestResults& results,
       std::vector<std::unique_ptr<SavePageRequest>> requests);
 
   // Start processing now if connected (but with conservative assumption
   // as to other device conditions).
   void StartProcessingIfConnected();
 
+  OfflinerImmediateStartStatus TryImmediateStart();
+
   // Check the request queue, and schedule a task corresponding
   // to the least restrictive type of request in the queue.
   void ScheduleAsNeeded();
 
   // Callback from the request picker when it has chosen our next request.
   void RequestPicked(const SavePageRequest& request);
 
   // Callback from the request picker when no more requests are in the queue.
   // The parameter is a signal for what (if any) conditions to schedule future
   // processing for.
@@ skipping 99 matching lines @@
   base::TimeDelta offliner_timeout_;
   // Allows us to pass a weak pointer to callbacks.
   base::WeakPtrFactory<RequestCoordinator> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RequestCoordinator);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_BACKGROUND_REQUEST_COORDINATOR_H_