[fileapp] Address TODO to remove code after CL:2526653

After chrome.metricsPrivate fakes landed, CL:2500642 does not need use
these window.metrics fakes. Remove them.

Bug: 1113981
Change-Id: Iefcd5881a31a147e9387a9a175723a571412e5d6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2531597
Auto-Submit: Noel Gordon <noel@chromium.org>
Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826174}

chromeos/components/file_manager/resources/file_manager_fakes.js

@@ -137,22 +137,6 @@ window.chrome.metricsPrivate = {
   recordValue: (metricName, value) => {},
 };
 
-// TODO(crbug.com/1113981): remove once chrome.metricsPrivate lands.
-/** @suppress {checkTypes} */
-window.metrics = {
-  recordEnum: function() {},
-  recordInterval: function() {},
-  recordSmallCount: function() {},
-  recordTime: function() {},
-  recordUserAction: function() {},
-  recordValue: function() {},
-  startInterval: function() {},
-};
-
-// TODO(crbug.com/1113981): remove once chrome.metricsPrivate lands.
-// eslint-disable-next-line
-var metrics = window.metrics;
-
 window.DriveSyncHandler = class extends EventTarget {
   /**
    * Returns the completed event name.