DirectX based screen capturer logic

webrtc/modules/desktop_capture/BUILD.gn

Index: webrtc/modules/desktop_capture/BUILD.gn
diff --git a/webrtc/modules/desktop_capture/BUILD.gn b/webrtc/modules/desktop_capture/BUILD.gn
index 894d9308e367b3da476d369a35269f7b9ac60954..95ce7254b35e420c54e4c5aa9bf102c6c49c3ccd 100644
--- a/webrtc/modules/desktop_capture/BUILD.gn
+++ b/webrtc/modules/desktop_capture/BUILD.gn
@@ -79,6 +79,8 @@ source_set("desktop_capture") {
     "win/scoped_thread_desktop.h",
     "win/screen_capture_utils.cc",
     "win/screen_capture_utils.h",
+    "win/screen_capturer_win_directx.cc",
+    "win/screen_capturer_win_directx.h",
     "win/screen_capturer_win_gdi.cc",
     "win/screen_capturer_win_gdi.h",
     "win/screen_capturer_win_magnifier.cc",
@@ -121,6 +123,13 @@ source_set("desktop_capture") {
     ]
   }
 
+  if (is_win) {
+    libs = [
+      "d3d11.lib",
+      "shcore.lib",

[Sergey Ulanov, 2016/05/19 18:12:09]

Do we have shcore.dll on windows 7? AFAICT it's there only starting Win8, so it
will need to be loaded dynamically.

[Hzj_jie, 2016/05/19 21:20:28]

Considering this function does not provide extra benefit, I revert the change
and use HDC instead.

+    ]
+  }
+
   configs += [ "../..:common_config" ]
   public_configs = [ "../..:common_inherited_config" ]