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..79b900f6e6df2b7bb084f0ee80d4fa41b5709418 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 +160,16 @@ SearchBox::~SearchBox() {
 }
 
 void SearchBox::LogEvent(NTPLoggingEventType event) {
+  // navigation_start in ms.
+  uint64 start = 1000 * (render_view()->GetMainRenderFrame()->GetWebFrame()->
+      performance().navigationStart());
+  uint64 now =
+      (base::TimeTicks::Now() - base::TimeTicks::UnixEpoch()).InMilliseconds();
+  DCHECK(now >= start);
+  uint64 delta = now - start;

[Dan Beam, 2015/03/17 17:17:19]

i'm really confused as to what everything here is doing...

why aren't you just doing

  Time::Now() - Time(navigationStart())

(or TimeTicks::Now() - TimeTicks(navigationStart()))?

[fserb, 2015/03/17 17:41:32]

I've tried my best to do it this way before, which would be the sanner way.

Except that Time/TimeTicks don't have constructors (nor static functions) that
receive timestamp as input. The closest thing it has is a function that gets an
int64 InternalValue, but navigationStart is not a proper internalValue.

Since navigationStart is a timestamp since epoch (converted from a TimeTicks), I
got the delta by getting the timestamp now (Now - UnixEpoch) and subtracting
from the navigationStart.

An alternative would be to ADD UnixEpoch to navigationStart, and use that as an
InternalValue, but it seems hackier to me, since I'm just guessing what the
InternalValue is supposed to be.

But maybe I missed something on base::TimeTicks? If I do what you suggest, I get
a huge number as output from the subtraction (like 1765681612ms).

+  DVLOG(1) << now << " - " << start << " = " << delta;

[Dan Beam, 2015/03/17 17:17:19]

remove debug logging... unless there's some purpose?

[fserb, 2015/03/17 17:41:32]

Done.

   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,