[Media Controls] Add UMA for rotate-to-fullscreen feature

third_party/WebKit/Source/modules/media_controls/MediaControlsOrientationLockDelegate.cpp

 // 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 "modules/media_controls/MediaControlsOrientationLockDelegate.h"
 
 #include "core/dom/TaskRunnerHelper.h"
 #include "core/events/Event.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/Screen.h"
@@ skipping 54 matching lines @@
   metadata_histogram.Count(static_cast<int>(metrics));
 }
 
 void RecordLockResult(LockResultMetrics metrics) {
   DEFINE_STATIC_LOCAL(EnumerationHistogram, lock_result_histogram,
                       ("Media.Video.FullscreenOrientationLock.LockResult",
                        static_cast<int>(LockResultMetrics::kMax)));
   lock_result_histogram.Count(static_cast<int>(metrics));
 }
 
+void RecordAutoRotateEnabled(bool enabled) {
+  DEFINE_STATIC_LOCAL(
+      BooleanHistogram, auto_rotate_histogram,
+      ("Media.Video.FullscreenOrientationLock.AutoRotateEnabled"));
+  auto_rotate_histogram.Count(enabled);
+}
+
 // WebLockOrientationCallback implementation that will not react to a success
 // nor a failure.
 class DummyScreenOrientationCallback : public WebLockOrientationCallback {
  public:
   void OnSuccess() override {}
   void OnError(WebLockOrientationError) override {}
 };
 
 }  // anonymous namespace
 
@@ skipping 118 matching lines @@
       WrapPersistent(this))));
 #else
   GotIsAutoRotateEnabledByUser(true);  // Assume always enabled on other OSes.
 #endif  // OS(ANDROID)
 }
 
 void MediaControlsOrientationLockDelegate::GotIsAutoRotateEnabledByUser(
     bool enabled) {
   monitor_.reset();
 
+  RecordAutoRotateEnabled(enabled);
+
   if (!enabled) {
     // Since the user has locked their screen orientation, prevent
     // MediaControlsRotateToFullscreenDelegate from exiting fullscreen by not
     // listening for deviceorientation events and instead continuing to hold the
     // orientation lock until the user exits fullscreen. This enables users to
     // watch videos in bed with their head facing sideways (which requires a
     // landscape screen orientation when the device is portrait and vice versa).
     // TODO(johnme): Ideally we would start listening for deviceorientation
     // events and allow rotating to exit if a user enables screen auto rotation
     // after we have locked to landscape. That would require listening for
@@ skipping 206 matching lines @@
                   WrapPersistent(this)),
               TimeDelta::FromMilliseconds(kUnlockDelayMs));
 }
 
 DEFINE_TRACE(MediaControlsOrientationLockDelegate) {
   EventListener::Trace(visitor);
   visitor->Trace(video_element_);
 }
 
 }  // namespace blink