Track plugin input event latency

content/renderer/render_widget.cc

 // 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.
 
 #include "content/renderer/render_widget.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/debug/trace_event_synthetic_delay.h"
@@ skipping 367 matching lines @@
       popup_type_(popup_type),
       pending_window_rect_count_(0),
       suppress_next_char_events_(false),
       is_accelerated_compositing_active_(false),
       was_accelerated_compositing_ever_active_(false),
       animation_update_pending_(false),
       invalidation_task_posted_(false),
       screen_info_(screen_info),
       device_scale_factor_(screen_info_.deviceScaleFactor),
       is_threaded_compositing_enabled_(false),
+      current_event_latency_info_(NULL),
       next_output_surface_id_(0),
 #if defined(OS_ANDROID)
       text_field_is_dirty_(false),
       outstanding_ime_acks_(0),
 #endif
       popup_origin_scale_for_emulation_(0.f),
       resizing_mode_selector_(new ResizingModeSelector()),
       context_menu_source_type_(ui::MENU_SOURCE_MOUSE) {
   if (!swapped_out)
     RenderProcess::current()->AddRefProcess();
@@ skipping 527 matching lines @@
 
 void RenderWidget::OnHandleInputEvent(const blink::WebInputEvent* input_event,
                                       const ui::LatencyInfo& latency_info,
                                       bool is_keyboard_shortcut) {
   handling_input_event_ = true;
   if (!input_event) {
     handling_input_event_ = false;
     return;
   }
 
+  current_event_latency_info_ = &latency_info;

[piman, 2014/04/25 01:59:43]

I fear potential early outs (some could be added later). This function is huge.
Can you use an AutoReset<LatencyInfo> for RAII goodness?

[Yufeng Shen (Slow to review), 2014/04/25 20:42:42]

Done.

+
   base::TimeTicks start_time;
   if (base::TimeTicks::IsHighResNowFastAndReliable())
     start_time = base::TimeTicks::HighResNow();
 
   const char* const event_name =
       WebInputEventTraits::GetName(input_event->type);
   TRACE_EVENT1("renderer", "RenderWidget::OnHandleInputEvent",
                "event", event_name);
   TRACE_EVENT_SYNTHETIC_DELAY_BEGIN("blink.HandleInputEvent");
   TRACE_EVENT_FLOW_STEP0(
@@ skipping 164 matching lines @@
     UpdateTextInputState(SHOW_IME_IF_NEEDED, FROM_NON_IME);
 #elif defined(USE_AURA)
   // Show the virtual keyboard if enabled and a user gesture triggers a focus
   // change.
   if (processed && (input_event->type == WebInputEvent::TouchEnd ||
       input_event->type == WebInputEvent::MouseUp))
     UpdateTextInputState(SHOW_IME_IF_NEEDED, FROM_IME);
 #endif
 
   TRACE_EVENT_SYNTHETIC_DELAY_END("blink.HandleInputEvent");
+  current_event_latency_info_ = NULL;
   handling_input_event_ = false;
 
   if (!prevent_default) {
     if (WebInputEvent::isKeyboardEventType(input_event->type))
       DidHandleKeyEvent();
     if (WebInputEvent::isMouseEventType(input_event->type))
       DidHandleMouseEvent(*(static_cast<const WebMouseEvent*>(input_event)));
     if (WebInputEvent::isTouchEventType(input_event->type))
       DidHandleTouchEvent(*(static_cast<const WebTouchEvent*>(input_event)));
   }
@@ skipping 1239 matching lines @@
 
 void RenderWidget::RegisterSwappedOutChildFrame(RenderFrameImpl* frame) {
   swapped_out_frames_.AddObserver(frame);
 }
 
 void RenderWidget::UnregisterSwappedOutChildFrame(RenderFrameImpl* frame) {
   swapped_out_frames_.RemoveObserver(frame);
 }
 
 }  // namespace content