[settings logging] Add accessibility enum to UKM metrics.

Bug: 1014839
Change-Id: I9104d53beebc430a285b570f640d671ffad91c8e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2029387Reviewed-by: Steven Holte <holte@chromium.org>
Reviewed-by: Tony Yeoman <tby@chromium.org>
Commit-Queue: Rachel Wong <wrong@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737197}

ash/system/machine_learning/user_settings_event.proto

@@ -28,6 +28,24 @@ message UserSettingsEvent {
       BRIGHTNESS = 8;
     }
 
+    enum AccessibilityId {
+      SPOKEN_FEEDBACK = 1;
+      SELECT_TO_SPEAK = 2;
+      DICTATION = 3;
+      HIGH_CONTRAST = 4;
+      MAGNIFIER = 5;
+      DOCKED_MAGNIFIER = 6;
+      LARGE_CURSOR = 7;
+      AUTO_CLICK = 8;
+      VIRTUAL_KEYBOARD = 9;
+      SWITCH_ACCESS = 10;
+      CARET_HIGHLIGHT = 11;
+      MONO_AUDIO = 12;
+      HIGHLIGHT_MOUSE_CURSOR = 13;
+      HIGHLIGHT_KEYBOARD_FOCUS = 14;
+      STICKY_KEYS = 15;
+    }
+
     // Randomly generated ID that links together settings events that occurred
     // at the same time.
     optional int32 event_id = 1;
@@ -39,6 +57,10 @@ message UserSettingsEvent {
     optional int32 previous_value = 4;
     // Value of the setting after the change.
     optional int32 current_value = 5;
+
+    // The accessibility setting that was changed. Only populated if
+    // |setting_id| is ACCESSIBILITY.
+    optional AccessibilityId accessibility_id = 6;
   }
 
   message Features {

tools/metrics/histograms/enums.xml

@@ -124,6 +124,24 @@ uploading your change for review.  These are checked by presubmit scripts.
   <int value="43" label="FLAG_RETRIEVE_INTERACTIVE_WINDOWS"/>
 </enum>
 
+<enum name="AccessibilityId">
+  <int value="1" label="SpokenFeedback"/>
+  <int value="2" label="SelectToSpeak"/>
+  <int value="3" label="Dictation"/>
+  <int value="4" label="HighContrast"/>
+  <int value="5" label="Magnifier"/>
+  <int value="6" label="DockedMagnifier"/>
+  <int value="7" label="LargeCursor"/>
+  <int value="8" label="AutoClick"/>
+  <int value="9" label="VirtualKeyboard"/>
+  <int value="10" label="SwitchAccess"/>
+  <int value="11" label="CaretHighlight"/>
+  <int value="12" label="MonoAudio"/>
+  <int value="13" label="HighlightMouseCursor"/>
+  <int value="14" label="HighlightKeyboardFocus"/>
+  <int value="15" label="StickyKeys"/>
+</enum>
+
 <enum name="AccessibilityImageLabelMode">
   <summary>
     Tracks what mode the user has selected for accessibility image labels,

tools/metrics/ukm/ukm.xml

@@ -10020,6 +10020,11 @@ be describing additional metrics about the same event.
   <summary>
     Contains information about user activities relating to settings changes.
   </summary>
+  <metric name="AccessibilityId" enum="AccessibilityId">
+    <summary>
+      The accessibility setting that was changed.
+    </summary>
+  </metric>
   <metric name="BatteryPercentage">
     <summary>
       Battery percentage from 0 to 100.