Replace scoped_ptr with unique_ptr everywhere

But keep #including scoped_ptr.h in .h files, so as not to break
WebRTC users who expect those .h files to give them rtc::scoped_ptr.

BUG=webrtc:5520

Review-Url: https://codereview.webrtc.org/1937693002
Cr-Commit-Position: refs/heads/master@{#12581}
diff --git a/webrtc/test/frame_generator_capturer.h b/webrtc/test/frame_generator_capturer.h
index 91ed843..2b34dd2 100644
--- a/webrtc/test/frame_generator_capturer.h
+++ b/webrtc/test/frame_generator_capturer.h
@@ -10,6 +10,7 @@
 #ifndef WEBRTC_TEST_FRAME_GENERATOR_CAPTURER_H_
 #define WEBRTC_TEST_FRAME_GENERATOR_CAPTURER_H_
 
+#include <memory>
 #include <string>
 
 #include "webrtc/base/criticalsection.h"
@@ -64,10 +65,10 @@
   Clock* const clock_;
   bool sending_;
 
-  rtc::scoped_ptr<EventTimerWrapper> tick_;
+  std::unique_ptr<EventTimerWrapper> tick_;
   rtc::CriticalSection lock_;
   rtc::PlatformThread thread_;
-  rtc::scoped_ptr<FrameGenerator> frame_generator_;
+  std::unique_ptr<FrameGenerator> frame_generator_;
 
   int target_fps_;
   VideoRotation fake_rotation_ = kVideoRotation_0;