Measure loading time of several tabs.

chrome/browser/automation/automation_provider_observers.cc

Index: chrome/browser/automation/automation_provider_observers.cc
diff --git a/chrome/browser/automation/automation_provider_observers.cc b/chrome/browser/automation/automation_provider_observers.cc
index cdb5de8b71e939126a27d2085035d068406a4b80..8b09fe5e4791cc30e78ad55a44f2c1dc6b8475a9 100644
--- a/chrome/browser/automation/automation_provider_observers.cc
+++ b/chrome/browser/automation/automation_provider_observers.cc
@@ -28,10 +28,31 @@
 #include "chrome/browser/chromeos/login/authentication_notification_details.h"
 #endif
 
+// Holds onto start and stop timestamps for a particular tab
+class InitialLoadObserver::TabTime {
+ public:
+  explicit TabTime(base::TimeTicks started)
+      : load_start_time_(started) {
+  }
+  void set_stop_time(base::TimeTicks stopped) {
+    load_stop_time_ = stopped;
+  }
+  base::TimeTicks stop_time() const {
+    return load_stop_time_;
+  }
+  base::TimeTicks start_time() const {
+    return load_start_time_;
+  }
+ private:
+  base::TimeTicks load_start_time_;
+  base::TimeTicks load_stop_time_;
+};
+
 InitialLoadObserver::InitialLoadObserver(size_t tab_count,
                                          AutomationProvider* automation)
     : automation_(automation),
-      outstanding_tab_count_(tab_count) {
+      outstanding_tab_count_(tab_count),
+      init_time_(base::TimeTicks::Now()) {
   if (outstanding_tab_count_ > 0) {
     registrar_.Add(this, NotificationType::LOAD_START,
                    NotificationService::AllSources());
@@ -48,11 +69,16 @@ void InitialLoadObserver::Observe(NotificationType type,
                                   const NotificationDetails& details) {
   if (type == NotificationType::LOAD_START) {
     if (outstanding_tab_count_ > loading_tabs_.size())
-      loading_tabs_.insert(source.map_key());
+      loading_tabs_.insert(TabTimeMap::value_type(
+          source.map_key(),
+          TabTime(base::TimeTicks::Now())));
   } else if (type == NotificationType::LOAD_STOP) {
     if (outstanding_tab_count_ > finished_tabs_.size()) {
-      if (loading_tabs_.find(source.map_key()) != loading_tabs_.end())
+      TabTimeMap::iterator iter = loading_tabs_.find(source.map_key());
+      if (iter != loading_tabs_.end()) {
         finished_tabs_.insert(source.map_key());
+        iter->second.set_stop_time(base::TimeTicks::Now());
+      }
       if (outstanding_tab_count_ == finished_tabs_.size())
         ConditionMet();
     }
@@ -61,6 +87,28 @@ void InitialLoadObserver::Observe(NotificationType type,
   }
 }
 
+DictionaryValue* InitialLoadObserver::GetTimingInformation() const {
+  ListValue* items = new ListValue;
+  for (TabTimeMap::const_iterator it = loading_tabs_.begin();
+       it != loading_tabs_.end();
+       ++it) {
+    DictionaryValue* item = new DictionaryValue;
+    base::TimeDelta delta_start = it->second.start_time() - init_time_;
+
+    item->SetReal(L"load_start_ms", delta_start.InMillisecondsF());
+    if (it->second.stop_time().is_null()) {
+      item->Set(L"load_stop_ms", Value::CreateNullValue());
+    } else {
+      base::TimeDelta delta_stop = it->second.stop_time() - init_time_;
+      item->SetReal(L"load_stop_ms", delta_stop.InMillisecondsF());
+    }
+    items->Append(item);
+  }
+  DictionaryValue* return_value = new DictionaryValue;
+  return_value->Set(L"tabs", items);
+  return return_value;
+}
+
 void InitialLoadObserver::ConditionMet() {
   registrar_.RemoveAll();
   automation_->Send(new AutomationMsg_InitialLoadsComplete(0));