Cursor Control: Add UMA counter

Records if a GestureScrollBegin is used as cursor control.

Bug: 1126778
Change-Id: Id0e9a8aec1c20f1eaf21d9a44dbfcb622b919fc4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2517900
Commit-Queue: Shimi Zhang <ctzsm@chromium.org>
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Reviewed-by: Changwan Ryu <changwan@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823846}

content/browser/renderer_host/input/touch_action_browsertest.cc

@@ -12,6 +12,7 @@
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/bind_test_util.h"
+#include "base/test/metrics/histogram_tester.h"
 #include "base/test/scoped_feature_list.h"
 #include "build/build_config.h"
 #include "content/browser/renderer_host/input/synthetic_gesture.h"
@@ -837,6 +838,7 @@ class TouchActionBrowserTestEnableCursorControl
 // scroll, and changes the selection.
 IN_PROC_BROWSER_TEST_F(TouchActionBrowserTestEnableCursorControl,
                        BasicCursorControl) {
+  base::HistogramTester histograms;
   LoadURL(kContentEditableDataURL.c_str());
 
   EXPECT_EQ(32,
@@ -855,6 +857,10 @@ IN_PROC_BROWSER_TEST_F(TouchActionBrowserTestEnableCursorControl,
 
   EXPECT_EQ(anchor_offset, focus_offset);
   EXPECT_GT(32, anchor_offset);
+  histograms.ExpectBucketCount("Blink.Input.GestureScrollBeginAsCursorControl",
+                               true, 1);
+  histograms.ExpectBucketCount("Blink.Input.GestureScrollBeginAsCursorControl",
+                               false, 0);
 }
 
 // Perform a horizontal swipe over an editable element from right to left (the
@@ -863,6 +869,7 @@ IN_PROC_BROWSER_TEST_F(TouchActionBrowserTestEnableCursorControl,
 // changed and scroll should happen.
 IN_PROC_BROWSER_TEST_F(TouchActionBrowserTestEnableCursorControl,
                        NoCursorControlForHorizontalScrollable) {
+  base::HistogramTester histograms;
   LoadURL(kContentEditableHorizontalScrollableDataURL.c_str());
 
   EXPECT_EQ(32,
@@ -883,6 +890,10 @@ IN_PROC_BROWSER_TEST_F(TouchActionBrowserTestEnableCursorControl,
   EXPECT_EQ(32, anchor_offset);
   EXPECT_LT(0.f, ExecuteScriptAndExtractDouble(
                      "document.getElementById('scroller').scrollLeft"));
+  histograms.ExpectBucketCount("Blink.Input.GestureScrollBeginAsCursorControl",
+                               true, 0);
+  histograms.ExpectBucketCount("Blink.Input.GestureScrollBeginAsCursorControl",
+                               false, 1);
 }
 
 // Perform a horizontal swipe over an editable element from right to left
@@ -914,6 +925,7 @@ IN_PROC_BROWSER_TEST_F(TouchActionBrowserTestEnableCursorControl,
 // scroll, and changes the selection.
 IN_PROC_BROWSER_TEST_F(TouchActionBrowserTestEnableCursorControl,
                        CursorControlOnInput) {
+  base::HistogramTester histograms;
   // input size larger than the text size, not horizontally scrollable.
   LoadURL(base::StringPrintf(kInputTagCursorControl.c_str(), 40).c_str());
 
@@ -931,12 +943,17 @@ IN_PROC_BROWSER_TEST_F(TouchActionBrowserTestEnableCursorControl,
 
   EXPECT_EQ(selection_start, selection_end);
   EXPECT_GT(32, selection_start);
+  histograms.ExpectBucketCount("Blink.Input.GestureScrollBeginAsCursorControl",
+                               true, 1);
+  histograms.ExpectBucketCount("Blink.Input.GestureScrollBeginAsCursorControl",
+                               false, 0);
 }
 
 // Perform a horizontal swipe over an horizontal scrollable input element from
 // right to left. Ensure the swipe is doing scrolling other than cursor control.
 IN_PROC_BROWSER_TEST_F(TouchActionBrowserTestEnableCursorControl,
                        NoCursorControlOnHorizontalScrollableInput) {
+  base::HistogramTester histograms;
   // Make the input size smaller than the text size, so it horizontally
   // scrollable.
   LoadURL(base::StringPrintf(kInputTagCursorControl.c_str(), 20).c_str());
@@ -955,6 +972,10 @@ IN_PROC_BROWSER_TEST_F(TouchActionBrowserTestEnableCursorControl,
 
   EXPECT_EQ(selection_start, selection_end);
   EXPECT_EQ(32, selection_start);
+  histograms.ExpectBucketCount("Blink.Input.GestureScrollBeginAsCursorControl",
+                               true, 0);
+  histograms.ExpectBucketCount("Blink.Input.GestureScrollBeginAsCursorControl",
+                               false, 1);
 }
 
 }  // namespace content

content/browser/renderer_host/input/touch_action_filter.cc

@@ -9,6 +9,7 @@
 #include "base/check_op.h"
 #include "base/debug/crash_logging.h"
 #include "base/debug/dump_without_crashing.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/notreached.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/trace_event/trace_event.h"
@@ -116,6 +117,8 @@ FilterGestureEventResult TouchActionFilter::FilterGestureEvent(
       FilterGestureEventResult res;
       if (!drop_scroll_events_) {
         SetCursorControlIfNecessary(gesture_event, touch_action);
+        UMA_HISTOGRAM_BOOLEAN("Blink.Input.GestureScrollBeginAsCursorControl",
+                              gesture_event->data.scroll_begin.cursor_control);
         res = FilterGestureEventResult::kFilterGestureEventAllowed;
       } else if (active_touch_action_.has_value()) {
         res = FilterGestureEventResult::kFilterGestureEventFiltered;

tools/metrics/histograms/histograms_xml/blink/histograms.xml

@@ -1042,6 +1042,14 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
+<histogram name="Blink.Input.GestureScrollBeginAsCursorControl"
+    enum="BooleanSuccess" expires_after="M89">
+  <owner>ctzsm@chromium.org</owner>
+  <owner>changwan@chromium.org</owner>
+  <owner>input-dev@chromium.org</owner>
+  <summary>Records if a GestureScrollBegin is for cursor control.</summary>
+</histogram>
+
 <histogram name="Blink.IntersectionObservation.UpdateTime" units="microseconds"
     expires_after="2021-03-21">
 <!-- Name completed by histogram_suffixes name="BlinkUpdateTimeAggregatedSuffixes" -->