[Mojo Video Capture] Simplify media::VideoCaptureDevice::Client:Buffer to a struct

media/capture/video/video_capture_device.cc

Index: media/capture/video/video_capture_device.cc
diff --git a/media/capture/video/video_capture_device.cc b/media/capture/video/video_capture_device.cc
index 5da33f01b7c39fcde86833e000fc04a04bbfd3da..df5f079bb15beb03569f6d9757259bfd55728562 100644
--- a/media/capture/video/video_capture_device.cc
+++ b/media/capture/video/video_capture_device.cc
@@ -13,8 +13,23 @@
 
 namespace media {
 
-VideoCaptureDevice::Client::Buffer::~Buffer() {
-}
+VideoCaptureDevice::Client::Buffer::Buffer() : id(0), frame_feedback_id(0) {}
+
+VideoCaptureDevice::Client::Buffer::Buffer(
+    int buffer_id,
+    int frame_feedback_id,
+    std::unique_ptr<BufferAccessProvider> access_provider)
+    : id(buffer_id),
+      frame_feedback_id(frame_feedback_id),
+      access_provider(std::move(access_provider)) {}
+
+VideoCaptureDevice::Client::Buffer::Buffer(
+    VideoCaptureDevice::Client::Buffer&& other) = default;
+
+VideoCaptureDevice::Client::Buffer::~Buffer() = default;
+
+VideoCaptureDevice::Client::Buffer& VideoCaptureDevice::Client::Buffer::
+operator=(VideoCaptureDevice::Client::Buffer&& other) = default;
 
 VideoCaptureDevice::~VideoCaptureDevice() {
 }