Add a way to send the resource percentage signal to the RC.

chrome/browser/android/offline_pages/prerendering_loader.cc

 // 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.
 
 #include "chrome/browser/android/offline_pages/prerendering_loader.h"
 
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 181 matching lines @@
   // Add this signal to signal_data_.
   AddLoadingSignal("Snapshotting");
 
   HandleLoadEvent();
 }
 
 bool PrerenderingLoader::IsLowbarMet() {
   return is_lowbar_met_;
 }
 
+void PrerenderingLoader::ObserveResourceTracking(
+    const Offliner::ResourceDataType type,
+    int64_t started_count,
+    int64_t completed_count) {
+  // Add the signal to extra data, and use for tracking.
+  if (type == Offliner::ResourceDataType::IMAGE) {
+    double percentage = 100 * static_cast<double>(completed_count) /
+                        static_cast<double>(started_count);
+    // TODO(petewil): Use actual signal type instead of hardcoding name.
+    signal_data_.SetDouble("ImagePercentage", percentage);
+    signal_data_.SetDouble("StartedImages", started_count);
+    signal_data_.SetDouble("CompletedImages", completed_count);
+  }
+}
+
 void PrerenderingLoader::HandleLoadEvent() {
   // If still loading, check if the load succeeded or not, then update
   // the internal state (LOADED for success or IDLE for failure) and post
   // callback.
   // Note: it is possible to receive a load event (e.g., if timeout-based)
   // after the request has completed via another path (e.g., canceled) so
   // the Loader may be idle at this point.
 
   if (IsIdle() || IsLoaded())
     return;
@@ skipping 65 matching lines @@
   if (adapter_->IsActive()) {
     adapter_->DestroyActive();
   }
   snapshot_controller_.reset(nullptr);
   session_contents_.reset(nullptr);
   state_ = State::IDLE;
   is_lowbar_met_ = false;
 }
 
 }  // namespace offline_pages