PDF Viewer: Add custom zoom metric

Bug: 1105701
Change-Id: I1f45d55f6eb744bc63885016e5e8a9b2b4571d48
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2311521Reviewed-by: John Lee <johntlee@chromium.org>
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#791506}

chrome/browser/resources/pdf/metrics.js

@@ -178,7 +178,11 @@ PDFMetrics.UserAction = {
   ZOOM_OUT_FIRST: 41,
   ZOOM_OUT: 42,
 
-  NUMBER_OF_ACTIONS: 43,
+  // Recorded when the custom zoom input field is modified.
+  ZOOM_CUSTOM_FIRST: 43,
+  ZOOM_CUSTOM: 44,
+
+  NUMBER_OF_ACTIONS: 45,
 };
 
 // Map from UserAction to the 'FIRST' action. These metrics are recorded
@@ -269,4 +273,8 @@ PDFMetrics.firstMap_ = new Map([
     PDFMetrics.UserAction.ZOOM_OUT,
     PDFMetrics.UserAction.ZOOM_OUT_FIRST,
   ],
+  [
+    PDFMetrics.UserAction.ZOOM_CUSTOM,
+    PDFMetrics.UserAction.ZOOM_CUSTOM_FIRST,
+  ],
 ]);

chrome/browser/resources/pdf/pdf_viewer_base.js

@@ -610,6 +610,7 @@ export class PDFViewerBaseElement extends PolymerElement {
    */
   onZoomChanged(e) {
     this.viewport_.setZoom(e.detail / 100);
+    PDFMetrics.record(PDFMetrics.UserAction.ZOOM_CUSTOM);
   }
 
   /** @protected */

chrome/test/data/pdf/metrics_test.js

@@ -115,6 +115,8 @@ chrome.test.runTests(function() {
       PDFMetrics.recordZoomAction(/*isZoomIn=*/ true);
       PDFMetrics.recordZoomAction(/*isZoomIn=*/ false);
       PDFMetrics.recordZoomAction(/*isZoomIn=*/ true);
+      PDFMetrics.record(PDFMetrics.UserAction.ZOOM_CUSTOM);
+      PDFMetrics.record(PDFMetrics.UserAction.ZOOM_CUSTOM);
 
       chrome.test.assertEq(
           {
@@ -122,7 +124,9 @@ chrome.test.runTests(function() {
             [PDFMetrics.UserAction.ZOOM_IN_FIRST]: 1,
             [PDFMetrics.UserAction.ZOOM_IN]: 3,
             [PDFMetrics.UserAction.ZOOM_OUT_FIRST]: 1,
-            [PDFMetrics.UserAction.ZOOM_OUT]: 2
+            [PDFMetrics.UserAction.ZOOM_OUT]: 2,
+            [PDFMetrics.UserAction.ZOOM_CUSTOM_FIRST]: 1,
+            [PDFMetrics.UserAction.ZOOM_CUSTOM]: 2
           },
           chrome.metricsPrivate.actionCounter);
       chrome.test.succeed();

tools/metrics/histograms/enums.xml

@@ -9539,6 +9539,8 @@ histogram as enum -->
   <int value="40" label="ZoomIn"/>
   <int value="41" label="ZoomOutFirst"/>
   <int value="42" label="ZoomOut"/>
+  <int value="43" label="ZoomCustomFirst"/>
+  <int value="44" label="ZoomCustom"/>
 </enum>
 
 <enum name="ChromePDFViewerAnnotationType">