Output DeviceName from various windows ScreenCapturer related implementations

webrtc/modules/desktop_capture/win/screen_capture_utils.cc

Index: webrtc/modules/desktop_capture/win/screen_capture_utils.cc
diff --git a/webrtc/modules/desktop_capture/win/screen_capture_utils.cc b/webrtc/modules/desktop_capture/win/screen_capture_utils.cc
index 9fa5c8b12db42a1816998c224ea25947b2b7b1ff..2dbb2690d1627a935d7ab116dd89554bff766e51 100644
--- a/webrtc/modules/desktop_capture/win/screen_capture_utils.cc
+++ b/webrtc/modules/desktop_capture/win/screen_capture_utils.cc
@@ -13,6 +13,7 @@
 #include <windows.h>
 
 #include "webrtc/rtc_base/checks.h"
+#include "webrtc/rtc_base/win32.h"
 
 namespace webrtc {
 
@@ -33,7 +34,7 @@ bool GetScreenList(DesktopCapturer::SourceList* screens) {
     if (!(device.StateFlags & DISPLAY_DEVICE_ACTIVE))
       continue;
 
-    screens->push_back({device_index, std::string()});
+    screens->push_back({device_index, rtc::ToUtf8(device.DeviceName)});

[Do not use (sergeyu), 2017/07/11 18:21:09]

title field is normally used for the title strings that can be shown to the
user. Does DeviceName contain a human-readable string?

[Hzj_jie, 2017/07/11 19:09:25]

The string is in format of \\.\Display{id}. But for screens, this field is not
used anyway.
(https://cs.chromium.org/chromium/src/chrome/browser/media/webrtc/native_deskt...)

[Sergey Ulanov, 2017/07/11 21:34:22]

Even if this field is not used right now it's still better to avoid reusing it
for anything that's not supposed to be shown to the user. Maybe add another
field in Source struct?

[Hzj_jie, 2017/07/11 21:48:32]

Done.

   }
   return true;
 }