ksv: Measure how long it takes to update for search result.

Report how long it takes to update the views hierarchy in response
to a search-string. Also report how long it takes before the update
is visible on screen.

BUG=865295

Change-Id: I103aa5cbd86be3189ab44121e72d375e6d742b4b
Reviewed-on: https://chromium-review.googlesource.com/1188755Reviewed-by: Tao Wu <wutao@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586111}

ash/components/shortcut_viewer/views/keyboard_shortcut_view.cc

@@ -414,6 +414,7 @@ void KeyboardShortcutView::UpdateViewsLayout(bool is_search_box_active) {
 
 void KeyboardShortcutView::ShowSearchResults(
     const base::string16& search_query) {
+  const base::TimeTicks start_time = base::TimeTicks::Now();
   search_results_container_->RemoveAllChildViews(true);
   auto* search_container_content_view = search_no_result_view_.get();
   auto found_items_list_view = std::make_unique<KeyboardShortcutItemListView>();
@@ -489,6 +490,21 @@ void KeyboardShortcutView::ShowSearchResults(
   search_results_container_->AddChildView(search_container_content_view);
   Layout();
   SchedulePaint();
+  constexpr int kBucketCount = 100;
+  UMA_HISTOGRAM_CUSTOM_MICROSECONDS_TIMES(
+      "Keyboard.ShortcutViewer.SearchUpdateTime",
+      base::TimeTicks::Now() - start_time,
+      base::TimeDelta::FromMicroseconds(50), base::TimeDelta::FromSeconds(1),
+      kBucketCount);
+  GetWidget()->GetCompositor()->RequestPresentationTimeForNextFrame(
+      base::BindOnce(
+          [](base::TimeTicks start_time,
+             const gfx::PresentationFeedback& feedback) {
+            UMA_HISTOGRAM_TIMES(
+                "Keyboard.ShortcutViewer.SearchUpdateTimeVisual",
+                feedback.timestamp - start_time);
+          },
+          start_time));
 }
 
 bool KeyboardShortcutView::CanMaximize() const {

tools/metrics/histograms/histograms.xml

@@ -38525,6 +38525,28 @@ uploading your change for review.
   </summary>
 </histogram>
 
+<histogram name="Keyboard.ShortcutViewer.SearchUpdateTime" units="microseconds">
+  <owner>jamescook@chromium.org</owner>
+  <owner>msw@chromium.org</owner>
+  <owner>wutao@chromium.org</owner>
+  <summary>
+    Time delay to make the visual update in response to a search-query. Note
+    that this does *not* include the initial delay to trigger the update after
+    the initial keystroke to change the search-query string.
+  </summary>
+</histogram>
+
+<histogram name="Keyboard.ShortcutViewer.SearchUpdateTimeVisual" units="ms">
+  <owner>jamescook@chromium.org</owner>
+  <owner>msw@chromium.org</owner>
+  <owner>wutao@chromium.org</owner>
+  <summary>
+    Time delay for the visual update to be visible on screen in response to a
+    search-query. Note that this does *not* include the initial delay to trigger
+    the update after the initial keystroke to change the search-query string.
+  </summary>
+</histogram>
+
 <histogram name="Keyboard.ShortcutViewer.StartupTime" units="ms">
   <owner>jamescook@chromium.org</owner>
   <owner>msw@chromium.org</owner>