Add metric Omnibox.FocusToOpenTime for time from omnibox focus to omnibox usage.

chrome/browser/ui/omnibox/omnibox_edit_model.cc

Index: chrome/browser/ui/omnibox/omnibox_edit_model.cc
===================================================================
--- chrome/browser/ui/omnibox/omnibox_edit_model.cc	(revision 214454)
+++ chrome/browser/ui/omnibox/omnibox_edit_model.cc	(working copy)
@@ -97,6 +97,10 @@
 // between focusing and editing the omnibox.
 const char kFocusToEditTimeHistogram[] = "Omnibox.FocusToEditTime";
 
+// Histogram name which counts the number of milliseconds a user takes
+// between focusing and opening an omnibox match.
+const char kFocusToOpenTimeHistogram[] = "Omnibox.FocusToOpenTime";
+
 void RecordPercentageMatchHistogram(const string16& old_text,
                                     const string16& new_text,
                                     bool search_term_replacement_active,
@@ -164,6 +168,7 @@
       controller_(controller),
       focus_state_(OMNIBOX_FOCUS_NONE),
       user_input_in_progress_(false),
+      user_input_since_focus_(true),
       just_deleted_text_(false),
       has_temporary_text_(false),
       paste_state_(NONE),
@@ -414,14 +419,11 @@
 }
 
 void OmniboxEditModel::SetInputInProgress(bool in_progress) {
-  if (in_progress && !last_omnibox_focus_without_user_input_.is_null()) {
+  if (in_progress && !user_input_since_focus_) {
     base::TimeTicks now = base::TimeTicks::Now();
-    DCHECK(last_omnibox_focus_without_user_input_ <= now);
-    UMA_HISTOGRAM_TIMES(kFocusToEditTimeHistogram,
-                        now - last_omnibox_focus_without_user_input_);
-    // We only want to count the time from focus to the first user input, so
-    // reset |last_omnibox_focus_without_user_input_| to null.
-    last_omnibox_focus_without_user_input_ = base::TimeTicks();
+    DCHECK(last_omnibox_focus_ <= now);

[Peter Kasting, 2013/08/01 18:19:44]

Nit: Does DCHECK_LE compile?

[H Fung, 2013/08/01 18:36:00]

It doesn't.  I think it's because operator<<(ostream, TimeTicks) isn't defined.

+    UMA_HISTOGRAM_TIMES(kFocusToEditTimeHistogram, now - last_omnibox_focus_);
+    user_input_since_focus_ = true;
   }
 
   if (user_input_in_progress_ == in_progress)
@@ -643,6 +645,8 @@
         << "omnibox text at same time or before the most recent time the "
         << "default match changed.";
 
+    UMA_HISTOGRAM_TIMES(kFocusToOpenTimeHistogram, now - last_omnibox_focus_);
+
     if (index != OmniboxPopupModel::kNoMatch)
       log.selected_index = index;
 
@@ -794,7 +798,8 @@
 }
 
 void OmniboxEditModel::OnSetFocus(bool control_down) {
-  last_omnibox_focus_without_user_input_ = base::TimeTicks::Now();
+  last_omnibox_focus_ = base::TimeTicks::Now();
+  user_input_since_focus_ = false;
 
   // If the omnibox lost focus while the caret was hidden and then regained
   // focus, OnSetFocus() is called and should restore visibility. Note that