mac: Add profiling for VideoCaptureDeviceFactoryMac::EnumerateDeviceNames

media/video/capture/mac/video_capture_device_factory_mac.mm

 // 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 "media/video/capture/mac/video_capture_device_factory_mac.h"
 
 #import <IOKit/audio/IOAudioTypes.h>
 
 #include "base/bind.h"
 #include "base/location.h"
+#include "base/profiler/scoped_tracker.h"
 #include "base/strings/string_util.h"
 #include "base/task_runner_util.h"
 #import "media/base/mac/avfoundation_glue.h"
 #import "media/video/capture/mac/video_capture_device_avfoundation_mac.h"
 #include "media/video/capture/mac/video_capture_device_mac.h"
 #import "media/video/capture/mac/video_capture_device_decklink_mac.h"
 #import "media/video/capture/mac/video_capture_device_qtkit_mac.h"
 
 namespace media {
 
@@ skipping 16 matching lines @@
     is_device_blacklisted = EndsWith(name.id(),
       kBlacklistedCameras[i].unique_id_signature, false);
   }
   DVLOG_IF(2, is_device_blacklisted) << "Blacklisted camera: " <<
       name.name() << ", id: " << name.id();
   return is_device_blacklisted;
 }
 
 static scoped_ptr<media::VideoCaptureDevice::Names>
 EnumerateDevicesUsingQTKit() {
+  // TODO(erikchen): Remove ScopedTracker below once crbug.com/458397 is fixed.

[mcasas, 2015/02/13 16:53:09]

Nit: Add http:// in front of crbug.com. Also below.

[erikchen, 2015/02/13 21:53:44]

Done.

+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "458397 media::EnumerateDevicesUsingQTKit"));
+
   scoped_ptr<VideoCaptureDevice::Names> device_names(
         new VideoCaptureDevice::Names());
   NSMutableDictionary* capture_devices =
       [[[NSMutableDictionary alloc] init] autorelease];
   [VideoCaptureDeviceQTKit getDeviceNames:capture_devices];
   for (NSString* key in capture_devices) {
     VideoCaptureDevice::Name name(
         [[[capture_devices valueForKey:key] deviceName] UTF8String],
         [key UTF8String], VideoCaptureDevice::Name::QTKIT);
     if (IsDeviceBlacklisted(name))
       name.set_is_blacklisted(true);
     device_names->push_back(name);
   }
   return device_names.Pass();
 }
 
 static void RunDevicesEnumeratedCallback(
     const base::Callback<void(scoped_ptr<media::VideoCaptureDevice::Names>)>&
         callback,
     scoped_ptr<media::VideoCaptureDevice::Names> device_names) {
+  // TODO(erikchen): Remove ScopedTracker below once crbug.com/458397 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "458397 media::RunDevicesEnumeratedCallback"));
   callback.Run(device_names.Pass());
 }
 
 // static
 bool VideoCaptureDeviceFactoryMac::PlatformSupportsAVFoundation() {
   return AVFoundationGlue::IsAVFoundationSupported();
 }
 
 VideoCaptureDeviceFactoryMac::VideoCaptureDeviceFactoryMac(
     scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner)
@@ skipping 18 matching lines @@
     if (!device->Init(device_name.capture_api_type())) {
       LOG(ERROR) << "Could not initialize VideoCaptureDevice.";
       capture_device.reset();
     }
   }
   return scoped_ptr<VideoCaptureDevice>(capture_device.Pass());
 }
 
 void VideoCaptureDeviceFactoryMac::GetDeviceNames(
     VideoCaptureDevice::Names* device_names) {
   DCHECK(thread_checker_.CalledOnValidThread());

[mcasas, 2015/02/13 16:53:09]

Shouldn't you check for jankiness here as well?
Video capture device enumeration uses either QTKit
xor AVFoundation based on a somewhat involved
casuistic, and this is the AVFoundation path.

[erikchen, 2015/02/13 21:53:44]

The particular source of jank that I'm tracking down has already been isolated
to the EnumerateDevicesUsingQTKit path. I just wanted to add a little bit more
granularity before passing off the task to someone who better knows the code.

That being said, there's no harm to adding some more profiling here - it's
possible that this path also has jankiness.

   // Loop through all available devices and add to |device_names|.
   NSDictionary* capture_devices;
   if (AVFoundationGlue::IsAVFoundationSupported()) {
     DVLOG(1) << "Enumerating video capture devices using AVFoundation";
     capture_devices = [VideoCaptureDeviceAVFoundation deviceNames];
     // Enumerate all devices found by AVFoundation, translate the info for each
     // to class Name and add it to |device_names|.
     for (NSString* key in capture_devices) {
       int transport_type = [[capture_devices valueForKey:key] transportType];
       // Transport types are defined for Audio devices and reused for video.
@@ skipping 72 matching lines @@
 }
 
 // static
 VideoCaptureDeviceFactory*
 VideoCaptureDeviceFactory::CreateVideoCaptureDeviceFactory(
     scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner) {
   return new VideoCaptureDeviceFactoryMac(ui_task_runner);
 }
 
 }  // namespace media