Files.app: Add UMA for HardUnplugged events.

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

Index: chrome/browser/chromeos/extensions/file_manager/device_event_router.cc
diff --git a/chrome/browser/chromeos/extensions/file_manager/device_event_router.cc b/chrome/browser/chromeos/extensions/file_manager/device_event_router.cc
index b6252e351c5844819ec597192efac2cd92e4bea7..47faf53631dc0f82ad2abbef1423db6a7beb1cf3 100644
--- a/chrome/browser/chromeos/extensions/file_manager/device_event_router.cc
+++ b/chrome/browser/chromeos/extensions/file_manager/device_event_router.cc
@@ -3,6 +3,7 @@
 // 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"
@@ -80,6 +81,13 @@ void DeviceEventRouter::OnDiskRemoved(
   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_MEDIUM_TIMES(
+          "FileBrowser.HardUnpluggedAroundSuspend.TimeSinceResume",
+          base::Time::Now() - last_suspend_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);
@@ -124,11 +132,18 @@ void DeviceEventRouter::OnFormatCompleted(const std::string& 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_MEDIUM_TIMES(
+        "FileBrowser.HardUnpluggedAroundSuspend.TimeUntilSuspend",
+        base::Time::Now() - last_hard_unplugged_);
+  }
   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,