Make V4L2CaptureDelegate non-ref-counted

media/capture/video/linux/v4l2_capture_delegate.cc

Index: media/capture/video/linux/v4l2_capture_delegate.cc
diff --git a/media/capture/video/linux/v4l2_capture_delegate.cc b/media/capture/video/linux/v4l2_capture_delegate.cc
index 2f16c203996b82851c6181e67ac4a3f07b96c8a6..3699bd324a880146609eae9bc2ebe3fec2ab2206 100644
--- a/media/capture/video/linux/v4l2_capture_delegate.cc
+++ b/media/capture/video/linux/v4l2_capture_delegate.cc
@@ -374,7 +374,8 @@ V4L2CaptureDelegate::V4L2CaptureDelegate(
       power_line_frequency_(power_line_frequency),
       is_capturing_(false),
       timeout_count_(0),
-      rotation_(0) {}
+      rotation_(0),
+      weak_factory_(this) {}
 
 void V4L2CaptureDelegate::AllocateAndStart(
     int width,
@@ -506,7 +507,8 @@ void V4L2CaptureDelegate::AllocateAndStart(
 
   // Post task to start fetching frames from v4l2.
   v4l2_task_runner_->PostTask(
-      FROM_HERE, base::Bind(&V4L2CaptureDelegate::DoCapture, this));
+      FROM_HERE,
+      base::Bind(&V4L2CaptureDelegate::DoCapture, weak_factory_.GetWeakPtr()));
 }
 
 void V4L2CaptureDelegate::StopAndDeAllocate() {
@@ -820,7 +822,8 @@ void V4L2CaptureDelegate::DoCapture() {
   }
 
   v4l2_task_runner_->PostTask(
-      FROM_HERE, base::Bind(&V4L2CaptureDelegate::DoCapture, this));
+      FROM_HERE,
+      base::Bind(&V4L2CaptureDelegate::DoCapture, weak_factory_.GetWeakPtr()));
 }
 
 void V4L2CaptureDelegate::SetErrorState(