Add TRACE_EVENT markers to various keyboard functions

ui/keyboard/keyboard_controller.cc

Index: ui/keyboard/keyboard_controller.cc
diff --git a/ui/keyboard/keyboard_controller.cc b/ui/keyboard/keyboard_controller.cc
index 5e88e8ea7a6af42c90907e8e72d3daae0c00edb4..4b68c515a8cb2f79d52e3f60cf5f95f12284ee16 100644
--- a/ui/keyboard/keyboard_controller.cc
+++ b/ui/keyboard/keyboard_controller.cc
@@ -246,6 +246,8 @@ void KeyboardController::NotifyKeyboardBoundsChanging(
 }
 
 void KeyboardController::HideKeyboard(HideReason reason) {
+  TRACE_EVENT0("vk", "HideKeyboard");

[yhanada, 2017/06/06 10:42:35]

Can you use longer name for the trace marker group? "virtual_keyboard"?

+
   keyboard_visible_ = false;
   ToggleTouchEventLogging(true);
 
@@ -377,6 +379,8 @@ void KeyboardController::OnTextInputStateChanged(
   if (!container_.get())
     return;
 
+  TRACE_EVENT0("vk", "OnTextInputStateChanged");
+
   ui::TextInputType type =
       client ? client->GetTextInputType() : ui::TEXT_INPUT_TYPE_NONE;
 
@@ -423,6 +427,8 @@ void KeyboardController::ShowKeyboardInternal(int64_t display_id) {
   // |Shell::CreateKeyboard| is called.
   DCHECK(container_.get());
 
+  TRACE_EVENT0("vk", "ShowKeyboardInternal");
+
   if (container_->children().empty()) {
     keyboard::MarkKeyboardLoadStarted();
     aura::Window* keyboard = ui_->GetKeyboardWindow();