Obsolete GPU.Output.ColorSpace histogram.

Will be replaced by a platform-agnostic one later.

Fixed: 1123574
Change-Id: I8bb240aad3e2e66a83e1366aa875b9c0cd3ad1a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2453892
Auto-Submit: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Robert Kaplow <rkaplow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814657}

tools/metrics/histograms/histograms_xml/gpu/histograms.xml

@@ -793,6 +793,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="GPU.Output.ColorSpace" enum="DXGI_COLOR_SPACE_TYPE"
     expires_after="2020-10-11">
+  <obsolete>
+    Will be replaced with a platform agnostic version. Removed Oct 2020.
+  </obsolete>
   <owner>hubbe@chromium.org</owner>
   <owner>media-dev@chromium.org</owner>
   <summary>

ui/gl/direct_composition_surface_win.cc

@@ -577,8 +577,6 @@ bool DirectCompositionSurfaceWin::IsHDRSupported() {
         continue;
       }
 
-      base::UmaHistogramSparse("GPU.Output.ColorSpace", desc.ColorSpace);
-
       if (desc.ColorSpace == DXGI_COLOR_SPACE_RGB_FULL_G2084_NONE_P2020) {
         hdr_monitor_found = true;
       }