Add time from navigation_start to NTP LogEvent

chrome/renderer/searchbox/searchbox.cc

Index: chrome/renderer/searchbox/searchbox.cc
diff --git a/chrome/renderer/searchbox/searchbox.cc b/chrome/renderer/searchbox/searchbox.cc
index 9adce8536714bf97658937ee385048a46db5c780..d1d71a7ffd9d0d0589fe1d66a6b05e7a81512b77 100644
--- a/chrome/renderer/searchbox/searchbox.cc
+++ b/chrome/renderer/searchbox/searchbox.cc
@@ -9,6 +9,7 @@
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/time/time.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/favicon/favicon_url_parser.h"
 #include "chrome/common/omnibox_focus_state.h"
@@ -16,10 +17,13 @@
 #include "chrome/common/url_constants.h"
 #include "chrome/renderer/searchbox/searchbox_extension.h"
 #include "components/favicon_base/favicon_types.h"
+#include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_view.h"
 #include "net/base/escape.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebFrame.h"
+#include "third_party/WebKit/public/web/WebLocalFrame.h"
+#include "third_party/WebKit/public/web/WebPerformance.h"
 #include "third_party/WebKit/public/web/WebView.h"
 #include "url/gurl.h"
 
@@ -156,8 +160,19 @@ SearchBox::~SearchBox() {
 }
 
 void SearchBox::LogEvent(NTPLoggingEventType event) {
+  // navigation_start in ms.
+  uint64 start = 1000 *
+                 render_view()
+                     ->GetMainRenderFrame()
+                     ->GetWebFrame()
+                     ->performance()
+                     .navigationStart();
+  uint64 now = (base::Time::Now() - base::Time::UnixEpoch()).InMilliseconds();

[kmadhusu, 2015/03/16 21:58:48]

I am not an expert to decide which function to use here. Based on the header
comments specified in
https://code.google.com/p/chromium/codesearch#chromium/src/base/time/time.h&t...,
"TimeTicks"  is guaranteed not to decrease whereas "Time" may actually decrease
or jump. I just wanted to make sure that you thought about it before using it
here. 

[fserb, 2015/03/16 22:05:32]

yeah, I saw that. But since I'm always using (now - epoch), it's pretty safe
either way. The reason I used TimeTicks (and maybe I should keep it) is because
navigationStart uses it too.

[kmadhusu, 2015/03/17 00:10:40]

Sure.

[fserb, 2015/03/17 15:54:49]

Acknowledged.

+  DCHECK(now >= start);
+  uint64 delta = now - start;
+  DVLOG(1) << now << " - " << start << " = " << delta;
   render_view()->Send(new ChromeViewHostMsg_LogEvent(
-      render_view()->GetRoutingID(), page_seq_no_, event));
+      render_view()->GetRoutingID(), page_seq_no_, event, delta));
 }
 
 void SearchBox::LogMostVisitedImpression(int position,