Metrics: Add user action for search+click -> right click

- Logs a user action when the user presses search+click
  combination to emulate right click.
- The action will only be counted when flags/settings are mapping
  search+click to right click. If the default alt-click
  behavior is enabled then pressing search+click won't be counted
- This is to measure the transition of users from the legacy
  alt+click behavior to the new search+click.
- Code that uses this is in a follow up CL

BUG=chromium:248762

Change-Id: Ia72520cd6dfcc0e2521c895b1e3bf298da28c95c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1603543
Commit-Queue: Zentaro Kavanagh <zentaro@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664584}

tools/metrics/actions/actions.xml

@@ -17075,6 +17075,15 @@ should be able to be added at any place in this file.
   <description>User interacts with an answer card.</description>
 </action>
 
+<action name="SearchClickMappedToRightClick">
+  <owner>zentaro@chromium.org</owner>
+  <description>
+    User pressed search click on a touchpad device to generate right click. This
+    is measuring the transition of use from the legacy alt click behaviour that
+    is tracked by AltClickMappedToRightClick.
+  </description>
+</action>
+
 <action name="SearchEngine_ManualChange">
   <owner>ianwen@chromium.org</owner>
   <description>

ui/chromeos/events/event_rewriter_chromeos.cc

@@ -623,11 +623,13 @@ bool EventRewriterChromeOS::ShouldRemapToRightClick(
   *matched_mask = 0;
   if (base::FeatureList::IsEnabled(
           ::chromeos::features::kUseSearchClickForRightClick)) {
-    if (AreFlagsSet(flags, kSearchLeftButton))
+    if (AreFlagsSet(flags, kSearchLeftButton)) {
       *matched_mask = kSearchLeftButton;
+    }
   } else {
-    if (AreFlagsSet(flags, kAltLeftButton))
+    if (AreFlagsSet(flags, kAltLeftButton)) {
       *matched_mask = kAltLeftButton;
+    }
   }
 
   return (*matched_mask != 0) &&
@@ -1294,7 +1296,14 @@ int EventRewriterChromeOS::RewriteModifierClick(
     *flags |= ui::EF_RIGHT_MOUSE_BUTTON;
     if (mouse_event.type() == ui::ET_MOUSE_PRESSED) {
       pressed_device_ids_.insert(mouse_event.source_device_id());
-      base::RecordAction(base::UserMetricsAction("AltClickMappedToRightClick"));
+      if (matched_mask == kSearchLeftButton) {
+        base::RecordAction(
+            base::UserMetricsAction("SearchClickMappedToRightClick"));
+      } else {
+        DCHECK(matched_mask == kAltLeftButton);
+        base::RecordAction(
+            base::UserMetricsAction("AltClickMappedToRightClick"));
+      }
     } else {
       pressed_device_ids_.erase(mouse_event.source_device_id());
     }