log the click activate/deactive of translate icon on location bar

chrome/browser/ui/views/translate/translate_icon_view.cc

Index: chrome/browser/ui/views/translate/translate_icon_view.cc
diff --git a/chrome/browser/ui/views/translate/translate_icon_view.cc b/chrome/browser/ui/views/translate/translate_icon_view.cc
index 1b1d24cabab6e50fc8058d8ad4f476ef1e977dc0..bf81a1aba7eb041dfa3065563dd00a6d43d19c84 100644
--- a/chrome/browser/ui/views/translate/translate_icon_view.cc
+++ b/chrome/browser/ui/views/translate/translate_icon_view.cc
@@ -4,9 +4,11 @@
 
 #include "chrome/browser/ui/views/translate/translate_icon_view.h"
 
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/ui/browser_commands.h"
+#include "chrome/browser/ui/translate/translate_bubble_view_state_transition.h"
 #include "chrome/browser/ui/view_ids.h"
 #include "chrome/browser/ui/views/translate/translate_bubble_view.h"
 #include "chrome/grit/generated_resources.h"
@@ -15,6 +17,12 @@
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/vector_icons_public.h"
 
+namespace {
+
+const char kTranslateBubbleUIEvent[] = "Translate.BubbleUiEvent";

[msw, 2016/05/11 18:51:35]

nit: define this string constant elsewhere for use here and in
translate_bubble_view.cc and translate_bubble_view_state_transition.cc

[ftang, 2016/05/11 23:20:23]

Done.

+
+}  // namespace
+
 TranslateIconView::TranslateIconView(CommandUpdater* command_updater)
     : BubbleIconView(command_updater, IDC_TRANSLATE_PAGE) {
   set_id(VIEW_ID_TRANSLATE_BUTTON);
@@ -23,6 +31,14 @@ TranslateIconView::TranslateIconView(CommandUpdater* command_updater)
 
 TranslateIconView::~TranslateIconView() {}
 
+void TranslateIconView::OnClicked(bool activated) {
+  UMA_HISTOGRAM_ENUMERATION(
+      kTranslateBubbleUIEvent,
+      (activated ? translate::OMNIBAR_ICON_CLICK_ACTIVATE
+                 : translate::OMNIBAR_ICON_CLICK_DEACTIVATE),
+      translate::TRANSLATE_BUBBLE_UI_EVENT_MAX);
+}
+
 void TranslateIconView::OnExecuting(
     BubbleIconView::ExecuteSource execute_source) {}