GTK: Add TRACE_EVENTs around gtk ui events.

chrome/browser/ui/gtk/download/download_item_gtk.cc

Index: chrome/browser/ui/gtk/download/download_item_gtk.cc
diff --git a/chrome/browser/ui/gtk/download/download_item_gtk.cc b/chrome/browser/ui/gtk/download/download_item_gtk.cc
index 54d449831adee274e182b93adcbc43315ea3e97c..d2990ca566163eedc64f39c37cbae66893432c5c 100644
--- a/chrome/browser/ui/gtk/download/download_item_gtk.cc
+++ b/chrome/browser/ui/gtk/download/download_item_gtk.cc
@@ -6,6 +6,7 @@
 
 #include "base/basictypes.h"
 #include "base/callback.h"
+#include "base/debug/trace_event.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/time.h"
@@ -699,6 +700,7 @@ void DownloadItemGtk::InitNineBoxes() {
 }
 
 gboolean DownloadItemGtk::OnHboxExpose(GtkWidget* widget, GdkEventExpose* e) {
+  TRACE_EVENT0("ui::gtk", "DownloadItemGtk::OnHboxExpose");
   if (theme_service_->UsingNativeTheme()) {
     int border_width = GTK_CONTAINER(widget)->border_width;
     int x = widget->allocation.x + border_width;
@@ -768,6 +770,7 @@ gboolean DownloadItemGtk::OnHboxExpose(GtkWidget* widget, GdkEventExpose* e) {
 }
 
 gboolean DownloadItemGtk::OnExpose(GtkWidget* widget, GdkEventExpose* e) {
+  TRACE_EVENT0("ui::gtk", "DownloadItemGtk::OnExpose");
   if (!theme_service_->UsingNativeTheme()) {
     bool is_body = widget == body_.get();
 
@@ -814,6 +817,7 @@ gboolean DownloadItemGtk::OnButtonPress(GtkWidget* button,
 
 gboolean DownloadItemGtk::OnProgressAreaExpose(GtkWidget* widget,
                                                GdkEventExpose* event) {
+  TRACE_EVENT0("ui::gtk", "DownloadItemGtk::OnProgressAreaExpose");
   // Create a transparent canvas.
   gfx::CanvasSkiaPaint canvas(event, false);
   if (complete_animation_.is_animating()) {
@@ -872,6 +876,7 @@ void DownloadItemGtk::ShowPopupMenu(GtkWidget* button,
 
 gboolean DownloadItemGtk::OnDangerousPromptExpose(GtkWidget* widget,
                                                   GdkEventExpose* event) {
+  TRACE_EVENT0("ui::gtk", "DownloadItemGtk::OnDangerousPromptExpose");
   if (!theme_service_->UsingNativeTheme()) {
     // The hbox renderer will take care of the border when in GTK mode.
     dangerous_nine_box_->RenderToWidget(widget);