Screen Enumeration: Basic implementation.

This CL exposes a subset of the screen properties outlined in the Screen
Enumeration API explainer:
https://github.com/spark008/screen-enumeration/blob/master/EXPLAINER.md.
The API is gated behind the experimental flag "ScreenEnumeration".

Bug: 994889
Change-Id: I3cd52f0bbfd4df11cd999bf1d21059bf298109f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1759890
Reviewed-by: Kinuko Yasuda <[email protected]>
Reviewed-by: Michael Wasserman <[email protected]>
Reviewed-by: Victor Costan <[email protected]>
Commit-Queue: Staphany Park <[email protected]>
Cr-Commit-Position: refs/heads/master@{#692420}
diff --git a/content/browser/BUILD.gn b/content/browser/BUILD.gn
index 7c8a677..f4fd88b 100644
--- a/content/browser/BUILD.gn
+++ b/content/browser/BUILD.gn
@@ -1639,6 +1639,8 @@
     "scheduler/scoped_do_not_use_ui_default_queue_from_io.h",
     "scoped_active_url.cc",
     "scoped_active_url.h",
+    "screen_enumeration/screen_enumeration_impl.cc",
+    "screen_enumeration/screen_enumeration_impl.h",
     "screen_orientation/screen_orientation_provider.cc",
     "screen_orientation/screen_orientation_provider.h",
     "screenlock_monitor/screenlock_monitor.cc",