Files.app: Add UMA for HardUnplugged events.

chrome/browser/chromeos/extensions/file_manager/device_event_router.cc

 // Copyright 2014 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 "base/bind.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/thread_task_runner_handle.h"
 #include "chrome/browser/chromeos/extensions/file_manager/device_event_router.h"
 #include "chrome/browser/chromeos/file_manager/volume_manager.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace file_manager {
 namespace {
 namespace file_manager_private = extensions::api::file_manager_private;
 using content::BrowserThread;
 }  // namespace
@@ skipping 57 matching lines @@
 void DeviceEventRouter::OnDiskRemoved(
     const chromeos::disks::DiskMountManager::Disk& disk) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (is_resuming_ || is_starting_up_)
     return;
 
   const std::string& device_path = disk.system_path_prefix();
   if (!disk.mount_path().empty() &&
       GetDeviceState(device_path) != DEVICE_HARD_UNPLUGGED_AND_REPORTED) {
+    // TODO(hirono): Remove the temporary UMA.  crbug.com/433734
+    if (!last_suspend_done_.is_null()) {
+      UMA_HISTOGRAM_CUSTOM_TIMES("FileBrowser.HardUnpluggedAfterResume",
+                                 base::Time::Now() - last_suspend_done_,
+                                 base::TimeDelta::FromMilliseconds(1),
+                                 base::TimeDelta::FromSeconds(30), 50);

[Alexei Svitkine (slow), 2014/11/25 17:48:12]

Nit: I suggest using UMA_HISTOGRAM_MEDIUM_TIMES(). The only difference is that
one has a cap of 3mins instead of 30s. But since we use exponential buckets, I
don't think it would be a big change to the distribution you're getting and it's
less custom code. Same for the one below.

[hirono, 2014/12/02 08:52:43]

Done.

+    }
+    last_hard_unplugged_ = base::Time::Now();
     OnDeviceEvent(file_manager_private::DEVICE_EVENT_TYPE_HARD_UNPLUGGED,
                   device_path);
     SetDeviceState(device_path, DEVICE_HARD_UNPLUGGED_AND_REPORTED);
   }
 }
 
 void DeviceEventRouter::OnVolumeMounted(chromeos::MountError error_code,
                                         const VolumeInfo& volume_info) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
@@ skipping 24 matching lines @@
                                           bool success) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   OnDeviceEvent(success ? file_manager_private::DEVICE_EVENT_TYPE_FORMAT_SUCCESS
                         : file_manager_private::DEVICE_EVENT_TYPE_FORMAT_FAIL,
                 device_path);
 }
 
 void DeviceEventRouter::SuspendImminent() {
   DCHECK(thread_checker_.CalledOnValidThread());
+  // TODO(hirono): Remove the temporary UMA.  crbug.com/433734
+  if (!last_hard_unplugged_.is_null()) {
+    UMA_HISTOGRAM_CUSTOM_TIMES("FileBrowser.HardUnpluggedBeforeSuspend",
+                               base::Time::Now() - last_hard_unplugged_,
+                               base::TimeDelta::FromMilliseconds(1),
+                               base::TimeDelta::FromSeconds(30), 50);
+  }
   is_resuming_ = true;
 }
 
 void DeviceEventRouter::SuspendDone(const base::TimeDelta& sleep_duration) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  last_suspend_done_ = base::Time::Now();
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE,
       base::Bind(&DeviceEventRouter::SuspendDoneDelayed,
                  weak_factory_.GetWeakPtr()),
       resume_time_delta_);
 }
 
 void DeviceEventRouter::SuspendDoneDelayed() {
   DCHECK(thread_checker_.CalledOnValidThread());
   is_resuming_ = false;
@@ skipping 12 matching lines @@
     device_states_[device_path] = state;
   } else {
     const std::map<std::string, DeviceState>::iterator it =
         device_states_.find(device_path);
     if (it != device_states_.end())
       device_states_.erase(it);
   }
 }
 
 }  // namespace file_manager