Instrument screen.internal and screen.primary for identifiability study.

Bug: 973801
Change-Id: I8fdbb4636af81675fc155e04b22488f535207bdd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2351957
Commit-Queue: Dylan Cutler <dylancutler@google.com>
Reviewed-by: Asanka Herath <asanka@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798452}

third_party/blink/public/mojom/web_feature/web_feature.mojom

@@ -2733,6 +2733,8 @@ enum WebFeature {
   kBluetoothRemoteGATTDescriptor_Uuid = 3403,
   kBluetoothRemoteGATTService_Uuid = 3404,
   kGPUAdapter_Name = 3405,
+  kWindowScreenInternal = 3406,
+  kWindowScreenPrimary = 3407,
 
   // Add new features immediately above this line. Don't change assigned
   // numbers of any item, and don't reuse removed slots.

third_party/blink/renderer/core/frame/screen.idl

@@ -47,8 +47,8 @@
     // https://github.com/webscreens/screen-enumeration
     [HighEntropy=Direct, MeasureAs=WindowScreenLeft, RuntimeEnabled=WindowPlacement] readonly attribute long left;
     [HighEntropy=Direct, MeasureAs=WindowScreenTop, RuntimeEnabled=WindowPlacement] readonly attribute long top;
-    [RuntimeEnabled=WindowPlacement] readonly attribute boolean internal;
-    [RuntimeEnabled=WindowPlacement] readonly attribute boolean primary;
+    [HighEntropy=Direct, MeasureAs=WindowScreenInternal, RuntimeEnabled=WindowPlacement] readonly attribute boolean internal;
+    [HighEntropy=Direct, MeasureAs=WindowScreenPrimary, RuntimeEnabled=WindowPlacement] readonly attribute boolean primary;
     [RuntimeEnabled=WindowPlacement] readonly attribute float scaleFactor;
     [RuntimeEnabled=WindowPlacement] readonly attribute DOMString id;
     [RuntimeEnabled=WindowPlacement] readonly attribute boolean touchSupport;

tools/metrics/histograms/enums.xml

@@ -28753,6 +28753,8 @@ Called by update_use_counter_feature_enum.py.-->
   <int value="3403" label="BluetoothRemoteGATTDescriptor_Uuid"/>
   <int value="3404" label="BluetoothRemoteGATTService_Uuid"/>
   <int value="3405" label="GPUAdapter_Name"/>
+  <int value="3406" label="WindowScreenInternal"/>
+  <int value="3407" label="WindowScreenPrimary"/>
 </enum>
 
 <enum name="FeaturePolicyAllowlistType">