Output DeviceName from various windows ScreenCapturer related implementations

webrtc/modules/desktop_capture/win/screen_capturer_win_directx.cc

Index: webrtc/modules/desktop_capture/win/screen_capturer_win_directx.cc
diff --git a/webrtc/modules/desktop_capture/win/screen_capturer_win_directx.cc b/webrtc/modules/desktop_capture/win/screen_capturer_win_directx.cc
index 74b7b4501a939ee90c33422d5fa7a311e595cfe9..3aa48320d5db82c8635ef0a7d94f13545e752636 100644
--- a/webrtc/modules/desktop_capture/win/screen_capturer_win_directx.cc
+++ b/webrtc/modules/desktop_capture/win/screen_capturer_win_directx.cc
@@ -12,6 +12,7 @@
 
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "webrtc/modules/desktop_capture/desktop_frame.h"
 #include "webrtc/rtc_base/checks.h"
@@ -110,9 +111,13 @@ void ScreenCapturerWinDirectx::CaptureFrame() {
 }
 
 bool ScreenCapturerWinDirectx::GetSourceList(SourceList* sources) {
-  int screen_count = controller_->ScreenCount();
-  for (int i = 0; i < screen_count; i++) {
-    sources->push_back({i});
+  std::vector<std::string> device_names;
+  if (!controller_->GetDeviceNames(&device_names)) {
+    return false;
+  }
+
+  for (int i = 0; i < static_cast<int>(device_names.size()); i++) {

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

Use size_t for i, then you wouldn't need the cast.

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

Then we will need to convert from size_t to int in the following line.
sources->push_back({static_cast<intptr_t>(i), device_names[i]});

+    sources->push_back({i, device_names[i]});
   }
   return true;
 }