History: Add load-time metric for non-MD and MD History WebUI

chrome/browser/ui/webui/metrics_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/metrics_handler.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
@@ skipping 16 matching lines @@
 
 void MetricsHandler::RegisterMessages() {
   web_ui()->RegisterMessageCallback(
       "metricsHandler:recordAction",
       base::Bind(&MetricsHandler::HandleRecordAction, base::Unretained(this)));
   web_ui()->RegisterMessageCallback(
       "metricsHandler:recordInHistogram",
       base::Bind(&MetricsHandler::HandleRecordInHistogram,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback(
+      "metricsHandler:recordTime",
+      base::Bind(&MetricsHandler::HandleRecordTime, base::Unretained(this)));
+  web_ui()->RegisterMessageCallback(
       "metricsHandler:logEventTime",
       base::Bind(&MetricsHandler::HandleLogEventTime, base::Unretained(this)));
 }
 
 void MetricsHandler::HandleRecordAction(const base::ListValue* args) {
   std::string string_action = base::UTF16ToUTF8(ExtractStringValue(args));
   content::RecordComputedAction(string_action);
 }
 
 void MetricsHandler::HandleRecordInHistogram(const base::ListValue* args) {
@@ skipping 23 matching lines @@
 
   // As |histogram_name| may change between calls, the UMA_HISTOGRAM_ENUMERATION
   // macro cannot be used here.
   base::HistogramBase* counter =
       base::LinearHistogram::FactoryGet(
           histogram_name, 1, int_boundary_value, bucket_count + 1,
           base::HistogramBase::kUmaTargetedHistogramFlag);
   counter->Add(int_value);
 }
 
+void MetricsHandler::HandleRecordTime(const base::ListValue* args) {
+  std::string histogram_name;
+  double value;
+
+  if (!args->GetString(0, &histogram_name) ||
+      !args->GetDouble(1, &value) ||
+      value < 0) {
+    NOTREACHED();
+    return;
+  }
+
+  base::TimeDelta time_value = base::TimeDelta::FromMilliseconds(value);
+
+  base::HistogramBase* counter = base::LinearHistogram::FactoryTimeGet(

[Ilya Sherman, 2016/08/04 07:13:56]

Hmm, I don't think you want a linear histogram -- I think you want a histogram
with exponentially spaced buckets.  I kind of suspect that this isn't the right
handler to add this code to... though I'm not sure where else the code might
live.  Basically, I'm surprised that there isn't already code to handle
recording non-linear histograms from WebUI pages.

[tsergeant, 2016/08/04 07:46:55]

Done, I've switched to base::Histogram.

I think that this is the best place we have for this code right now, and there's
actually an old bug (crbug.com/104338) to add this, among other things.

[Ilya Sherman, 2016/08/04 20:01:10]

Did you mean to upload a newer patch set?

[tsergeant, 2016/08/04 22:45:19]

Oops, done

[Dan Beam, 2016/08/04 22:50:37]

yeahhhh, but that bug (and its filer) are silly

+      histogram_name, base::TimeDelta::FromMilliseconds(1),
+      base::TimeDelta::FromSeconds(10), 50,
+      base::HistogramBase::kUmaTargetedHistogramFlag);
+  counter->AddTime(time_value);
+}
+
 void MetricsHandler::HandleLogEventTime(const base::ListValue* args) {
   std::string event_name = base::UTF16ToUTF8(ExtractStringValue(args));
   WebContents* tab = web_ui()->GetWebContents();
 
   // Not all new tab pages get timed. In those cases, we don't have a
   // new_tab_start_time_.
   CoreTabHelper* core_tab_helper = CoreTabHelper::FromWebContents(tab);
   if (core_tab_helper->new_tab_start_time().is_null())
     return;
 
   base::TimeDelta duration =
       base::TimeTicks::Now() - core_tab_helper->new_tab_start_time();
 
   if (event_name == "Tab.NewTabScriptStart") {
     UMA_HISTOGRAM_TIMES("Tab.NewTabScriptStart", duration);
   } else if (event_name == "Tab.NewTabDOMContentLoaded") {
     UMA_HISTOGRAM_TIMES("Tab.NewTabDOMContentLoaded", duration);
   } else if (event_name == "Tab.NewTabOnload") {
     UMA_HISTOGRAM_TIMES("Tab.NewTabOnload", duration);
     // The new tab page has finished loading; reset it.
     CoreTabHelper* core_tab_helper = CoreTabHelper::FromWebContents(tab);
     core_tab_helper->set_new_tab_start_time(base::TimeTicks());
   } else {
     NOTREACHED();
   }
 }