Revert of RELAND: ImageCapture: Implement takePhoto() for Mac AVFoundation

media/capture/video/mac/video_capture_device_mac.mm

Index: media/capture/video/mac/video_capture_device_mac.mm
diff --git a/media/capture/video/mac/video_capture_device_mac.mm b/media/capture/video/mac/video_capture_device_mac.mm
index 6ae6b8c1d8c8ef7a6ed3e71551f2842c00b25af0..f032280d68e9a150dc54e94220a5323d7de32b38 100644
--- a/media/capture/video/mac/video_capture_device_mac.mm
+++ b/media/capture/video/mac/video_capture_device_mac.mm
@@ -389,17 +389,6 @@
   state_ = kIdle;
 }
 
-void VideoCaptureDeviceMac::TakePhoto(TakePhotoCallback callback) {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-  DCHECK(state_ == kCapturing) << state_;
-
-  if (photo_callback_)  // Only one picture can be in flight at a time.
-    return;
-
-  photo_callback_.reset(new TakePhotoCallback(std::move(callback)));
-  [capture_device_ takePhoto];
-}
-
 bool VideoCaptureDeviceMac::Init(
     VideoCaptureDevice::Name::CaptureApiType capture_api_type) {
   DCHECK(task_runner_->BelongsToCurrentThread());
@@ -424,6 +413,8 @@
                                          int aspect_numerator,
                                          int aspect_denominator,
                                          base::TimeDelta timestamp) {
+  // This method is safe to call from a device capture thread, i.e. any thread
+  // controlled by AVFoundation.
   if (capture_format_.frame_size != frame_format.frame_size) {
     ReceiveError(FROM_HERE,
                  "Captured resolution " + frame_format.frame_size.ToString() +
@@ -433,26 +424,6 @@
 
   client_->OnIncomingCapturedData(video_frame, video_frame_length, frame_format,
                                   0, base::TimeTicks::Now(), timestamp);
-}
-
-void VideoCaptureDeviceMac::OnPhotoTaken(const uint8_t* image_data,
-                                         size_t image_length,
-                                         const std::string& mime_type) {
-  DCHECK(photo_callback_);
-  if (!image_data || !image_length) {
-    OnPhotoError();
-    return;
-  }
-
-  photo_callback_->Run(mojo::String::From(mime_type),
-                       mojo::Array<uint8_t>(std::vector<uint8_t>(
-                           image_data, image_data + image_length)));
-  photo_callback_.reset();
-}
-
-void VideoCaptureDeviceMac::OnPhotoError() {
-  DLOG(ERROR) << __FUNCTION__ << " error taking picture";
-  photo_callback_.reset();
 }
 
 void VideoCaptureDeviceMac::ReceiveError(