Histogram the scheme of an origin on the 1st navigation to it.

chrome/browser/profiles/profile_io_data.cc

Index: chrome/browser/profiles/profile_io_data.cc
diff --git a/chrome/browser/profiles/profile_io_data.cc b/chrome/browser/profiles/profile_io_data.cc
index c4e0cd99ea99340dd0a1c09db223a65b0e501053..f3cac9981a86301827bb88e21ba94fdcab1d5cd3 100644
--- a/chrome/browser/profiles/profile_io_data.cc
+++ b/chrome/browser/profiles/profile_io_data.cc
@@ -864,6 +864,12 @@ bool ProfileIOData::IsOffTheRecord() const {
       || profile_type() == Profile::GUEST_PROFILE;

[felt, 2016/04/01 00:04:50]

Ah yes, here... this version includes both INCOGNITO and GUEST profiles in the
definition of OTR.

[palmer, 2016/04/05 23:42:18]

Acknowledged.

 }
 
+bool ProfileIOData::HaveAlreadySeenOrigin(const url::Origin& origin) {
+  DCHECK(IsOffTheRecord()) << "Only code running Off The Record should call "
+                           << __PRETTY_FUNCTION__;
+  return false;
+}
+
 void ProfileIOData::InitializeMetricsEnabledStateOnUIThread() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 #if BUILDFLAG(ANDROID_JAVA_UI)