Add Keyboard Latency UMA Metrics.

chrome/browser/ui/cocoa/find_bar/find_bar_cocoa_controller.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/auto_reset.h"
 #include "base/mac/bundle_locations.h"
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/app/vector_icons/vector_icons.h"
@@ skipping 277 matching lines @@
     content::WebContents* web_contents =
         findBarBridge_->GetFindBarController()->web_contents();
     if (!web_contents)
       return NO;
 
     // Sanity-check to make sure we got a keyboard event.
     NSEvent* event = [NSApp currentEvent];
     if ([event type] != NSKeyDown && [event type] != NSKeyUp)
       return NO;
 
-    // Forward the event to the renderer.
-    // TODO(rohitrao): Should this call -[BaseView keyEvent:]?  Is there code in
-    // that function that we want to keep or avoid? Calling
-    // |ForwardKeyboardEvent()| directly ignores edit commands, which breaks
-    // cmd-up/down if we ever decide to include |moveToBeginningOfDocument:| in
-    // the list above.
+    // Forward the event to the renderer.  TODO(rohitrao): Should this call

[mfomitchev, 2017/04/04 14:59:05]

TODO should be on a new line?

[tdresser, 2017/05/01 15:49:21]

Done.

+    // -[BaseView keyEvent:]?  Is there code in that function that we want to
+    // keep or avoid? Calling |ForwardKeyboardEventWithLatencyInfo()| directly
+    // ignores edit commands, which breaks cmd-up/down if we ever decide to
+    // include |moveToBeginningOfDocument:| in the list above.
     content::RenderViewHost* render_view_host =
         web_contents->GetRenderViewHost();
-    render_view_host->GetWidget()->ForwardKeyboardEvent(
-        NativeWebKeyboardEvent(event));
+    render_view_host->GetWidget()->ForwardKeyboardEventWithLatencyInfo(
+        NativeWebKeyboardEvent(event), ui::LatencyInfo());

[mfomitchev, 2017/04/04 14:59:05]

Do we care about latency info on Mac? If yes, maybe we could copy the creation
timestamp from NSEvent to create a useful LatencyInfo here?

[tdresser, 2017/05/01 15:49:21]

We have terrible coverage currently.

I've added the UI component, and filed a bug for adding the original components,
as the other input types are also missing them.

https://bugs.chromium.org/p/chromium/issues/detail?id=708520

     return YES;
   }
 
   return NO;
 }
 
 // Methods from FindBar
 - (void)showFindBar:(BOOL)animate {
   // Save the currently-focused view.  |findBarView_| is in the view
   // hierarchy by now.  showFindBar can be called even when the
@@ skipping 343 matching lines @@
 }
 
 - (BrowserWindowController*)browserWindowController {
   if (!browser_)
     return nil;
   return [BrowserWindowController
       browserWindowControllerForWindow:browser_->window()->GetNativeWindow()];
 }
 
 @end