Add Keyboard Latency UMA Metrics.

content/browser/renderer_host/input/render_widget_host_latency_tracker.cc

 // Copyright 2014 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.
 
 #include "content/browser/renderer_host/input/render_widget_host_latency_tracker.h"
 
 #include <stddef.h>
 
 #include "base/logging.h"
 #include "base/metrics/histogram_functions.h"
@@ skipping 85 matching lines @@
     WebInputEvent::Type type,
     int64_t latency_component_id,
     const LatencyInfo& latency,
     InputEventAckState ack_result) {
   // If this event was coalesced into another event, ignore it, as the event it
   // was coalesced into will reflect the full latency.
   if (latency.coalesced())
     return;
 
   if (type != blink::WebInputEvent::kMouseWheel &&
-      !WebInputEvent::IsTouchEventType(type)) {
+      !WebInputEvent::IsTouchEventType(type) &&
+      !WebInputEvent::IsKeyboardEventType(type)) {
     return;
   }
 
   LatencyInfo::LatencyComponent rwh_component;
   if (!latency.FindLatency(ui::INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT,
                            latency_component_id, &rwh_component)) {
     return;
   }
   DCHECK_EQ(rwh_component.event_count, 1u);
 
   bool multi_finger_touch_gesture =
       WebInputEvent::IsTouchEventType(type) && active_multi_finger_gesture_;
 
   LatencyInfo::LatencyComponent ui_component;
   if (latency.FindLatency(ui::INPUT_EVENT_LATENCY_UI_COMPONENT, 0,
                           &ui_component)) {
     DCHECK_EQ(ui_component.event_count, 1u);
     base::TimeDelta ui_delta =
         rwh_component.last_event_time - ui_component.first_event_time;
 
     if (type == blink::WebInputEvent::kMouseWheel) {
       UMA_HISTOGRAM_CUSTOM_COUNTS("Event.Latency.Browser.WheelUI",
                                   ui_delta.InMicroseconds(), 1, 20000, 100);
-    } else {
-      DCHECK(WebInputEvent::IsTouchEventType(type));
+    } else if (WebInputEvent::IsTouchEventType(type)) {
       UMA_HISTOGRAM_CUSTOM_COUNTS("Event.Latency.Browser.TouchUI",
                                   ui_delta.InMicroseconds(), 1, 20000, 100);
+    } else if (WebInputEvent::IsKeyboardEventType(type)) {
+      UMA_HISTOGRAM_CUSTOM_COUNTS("Event.Latency.Browser.KeyUI",
+                                  ui_delta.InMicroseconds(), 1, 20000, 50);
+    } else {
+      // We should only report these histograms for wheel, touch and keyboard.
+      NOTREACHED();
     }
   }
 
-  // Both tap and scroll gestures depend on the disposition of the touch start
-  // and the current touch. For touch start, touch_start_default_prevented_ ==
-  // (ack_result == INPUT_EVENT_ACK_STATE_CONSUMED).
+  // Touchscreen tap and scroll gestures depend on the disposition of the touch
+  // start and the current touch. For touch start,
+  // touch_start_default_prevented_ == (ack_result ==
+  // INPUT_EVENT_ACK_STATE_CONSUMED).
   bool action_prevented = touch_start_default_prevented_ ||
                           ack_result == INPUT_EVENT_ACK_STATE_CONSUMED;
 
   std::string event_name = WebInputEvent::GetName(type);
+  if (WebInputEvent::IsKeyboardEventType(type))
+    event_name = "KeyEvent";
 
   std::string default_action_status =
       action_prevented ? "DefaultPrevented" : "DefaultAllowed";
 
   LatencyInfo::LatencyComponent main_component;
   if (latency.FindLatency(ui::INPUT_EVENT_LATENCY_RENDERER_MAIN_COMPONENT, 0,
                           &main_component)) {
     DCHECK_EQ(main_component.event_count, 1u);
     if (!multi_finger_touch_gesture) {
       UMA_HISTOGRAM_INPUT_LATENCY_MILLISECONDS(
@@ skipping 151 matching lines @@
     sample->SetUInt64Field(
         "Latency",
         (end_component.last_event_time - start_component.first_event_time)
             .InMicroseconds(),
         rappor::NO_NOISE);
     rappor_service->RecordSample(name, std::move(sample));
   }
 }
 
 }  // namespace content