Record usage of Geolocation API calls

Add MeasureAs attributes for geolocation methods so usage of the feature
can be tracked through UseCounter.

BUG=780267

Change-Id: I8994be04aa750971204f515d66f5834ce38ab8c8
Reviewed-on: https://chromium-review.googlesource.com/747862Reviewed-by: Vincent Scheib <scheib@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Vincent Scheib <scheib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#513031}

third_party/WebKit/Source/modules/geolocation/Geolocation.idl

@@ -27,12 +27,18 @@
 [
     NoInterfaceObject
 ] interface Geolocation {
-    [LogActivity] void getCurrentPosition(
+    [
+        LogActivity,
+        MeasureAs=GeolocationGetCurrentPosition
+    ] void getCurrentPosition(
         PositionCallback successCallback,
         optional PositionErrorCallback errorCallback,
         optional PositionOptions options);
 
-    [LogActivity] long watchPosition(
+    [
+        LogActivity,
+        MeasureAs=GeolocationWatchPosition
+    ] long watchPosition(
         PositionCallback successCallback,
         optional PositionErrorCallback errorCallback,
         optional PositionOptions options);

third_party/WebKit/public/platform/web_feature.mojom

@@ -1743,6 +1743,8 @@ enum WebFeature {
   kDocumentGetPreferredStylesheetSet = 2211,
   kDocumentGetSelectedStylesheetSet = 2212,
   kDocumentSetSelectedStylesheetSet = 2213,
+  kGeolocationGetCurrentPosition = 2214,
+  kGeolocationWatchPosition = 2215,
 
   // Add new features immediately above this line. Don't change assigned
   // numbers of any item, and don't reuse removed slots.

tools/metrics/histograms/enums.xml

@@ -16858,6 +16858,8 @@ uploading your change for review.  These are checked by presubmit scripts.
   <int value="2211" label="DocumentGetPreferredStylesheetSet"/>
   <int value="2212" label="DocumentGetSelectedStylesheetSet"/>
   <int value="2213" label="DocumentSetSelectedStylesheetSet"/>
+  <int value="2214" label="GeolocationGetCurrentPosition"/>
+  <int value="2215" label="GeolocationWatchPosition"/>
 </enum>
 
 <enum name="FeedbackSource">