FontAccess: Basic usage metrics

Adds basic usage metrics to the main API methods. This will give us a
basic quantitative view on how the API is used during Origin Trial.

Fixed: 1116107
Change-Id: I79e2717f49b645eac5f065c7b5346ca10b3521ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2354607
Commit-Queue: Olivier Yiptong <oyiptong@chromium.org>
Reviewed-by: Martin Barbella <mbarbella@chromium.org>
Reviewed-by: Joshua Bell <jsbell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797958}

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

@@ -2712,6 +2712,9 @@ enum WebFeature {
   kPhoneFieldDetected_PredictedTypeMatch = 3381,
   kEmailFieldDetected_PatternMatch = 3382,
   kLastLetterSpacingAffectsRendering = 3383,
+  kV8FontMetadata_GetTables_Method = 3384,
+  kV8FontMetadata_Blob_Method = 3385,
+  kV8FontManager_Query_Method = 3386,
 
   // 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/modules/font_access/font_manager.idl

@@ -9,5 +9,5 @@
     SecureContext,
     RuntimeEnabled=FontAccess
 ] interface FontManager {
-    [CallWith=ScriptState] object query();
+  [CallWith=ScriptState, Measure] object query();
 };

third_party/blink/renderer/modules/font_access/font_metadata.idl

@@ -11,6 +11,6 @@
   readonly attribute USVString postscriptName;
   readonly attribute USVString fullName;
   readonly attribute USVString family;
-  [CallWith=ScriptState] Promise<FontTableMap> getTables(optional sequence<ByteString> tables);
-  [CallWith=ScriptState] Promise<Blob> blob();
+  [CallWith=ScriptState, Measure] Promise<FontTableMap> getTables(optional sequence<ByteString> tables);
+  [CallWith=ScriptState, Measure] Promise<Blob> blob();
 };

tools/metrics/histograms/enums.xml

@@ -28721,6 +28721,9 @@ Called by update_use_counter_feature_enum.py.-->
   <int value="3381" label="PhoneFieldDetected_PredictedTypeMatch"/>
   <int value="3382" label="EmailFieldDetected_PatternMatch"/>
   <int value="3383" label="LastLetterSpacingAffectsRendering"/>
+  <int value="3384" label="V8FontMetadata_GetTables_Method"/>
+  <int value="3385" label="V8FontMetadata_Blob_Method"/>
+  <int value="3386" label="V8FontManager_Query_Method"/>
 </enum>
 
 <enum name="FeaturePolicyAllowlistType">