Remove predictor metrics

These metrics are unmonitored, and the predictor is being replaced by
a new system.

Bug: 831006
Change-Id: I2f3260637581960b059319e92f434091426252bb
Reviewed-on: https://chromium-review.googlesource.com/1057461Reviewed-by: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Alexandr Ilin <alexilin@chromium.org>
Commit-Queue: Charlie Harrison <csharrison@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558670}

chrome/browser/net/predictor.cc

@@ -661,8 +661,6 @@ void Predictor::FinalizeInitializationOnIOThread(
     DnsPrefetchMotivatedList(startup_urls, UrlInfo::STARTUP_LIST_MOTIVATED);
 
   DeserializeReferrers(*referral_list);
-
-  LogStartupMetrics();
 }
 
 //-----------------------------------------------------------------------------
@@ -809,8 +807,6 @@ void Predictor::PreconnectUrlOnIOThread(
   if (!getter)
     return;
 
-  UMA_HISTOGRAM_ENUMERATION("Net.PreconnectMotivation", motivation,
-                            UrlInfo::MAX_MOTIVATED);
   content::PreconnectUrl(getter, url, site_for_cookies, count,
                          allow_credentials);
 }
@@ -893,14 +889,9 @@ void Predictor::PrepareFrameSubresources(const GURL& original_url,
       UrlInfo::LEARNED_REFERAL_MOTIVATED;
   for (std::map<GURL, ReferrerValue>::iterator future_url = referrer->begin();
        future_url != referrer->end();) {
-    SubresourceValue evalution(TOO_NEW);
     double connection_expectation = future_url->second.subresource_use_rate();
-    UMA_HISTOGRAM_CUSTOM_COUNTS("Net.PreconnectSubresourceExpectation",
-                                static_cast<int>(connection_expectation * 100),
-                                10, 5000, 50);
     future_url->second.ReferrerWasObserved();
     if (connection_expectation > kPreconnectWorthyExpectedValue) {
-      evalution = PRECONNECTION;
       future_url->second.IncrementPreconnectionCount();
       int count = static_cast<int>(std::ceil(connection_expectation));
       if (url.host_piece() == future_url->first.host_piece())
@@ -908,7 +899,6 @@ void Predictor::PrepareFrameSubresources(const GURL& original_url,
       PreconnectUrlOnIOThread(future_url->first, site_for_cookies, motivation,
                               kAllowCredentialsOnPreconnectByDefault, count);
     } else if (connection_expectation > kDNSPreresolutionWorthyExpectedValue) {
-      evalution = PRERESOLUTION;
       future_url->second.preresolution_increment();
       AppendToResolutionQueue(future_url->first, motivation);
     }
@@ -920,8 +910,6 @@ void Predictor::PrepareFrameSubresources(const GURL& original_url,
     } else {
       ++future_url;
     }
-    UMA_HISTOGRAM_ENUMERATION("Net.PreconnectSubresourceEval", evalution,
-                              SUBRESOURCE_VALUE_MAX);
   }
   // If the Referrer has no URLs associated with it, remove it from the map.
   if (referrer->empty())
@@ -1066,21 +1054,6 @@ GURL Predictor::GetHSTSRedirectOnIOThread(const GURL& url) {
   return url.ReplaceComponents(replacements);
 }
 
-void Predictor::LogStartupMetrics() {
-  size_t total_bytes = 0;
-  for (const auto& referrer : referrers_) {
-    total_bytes += referrer.first.spec().size();
-    total_bytes += sizeof(Referrer);
-    for (const auto& subresource : referrer.second) {
-      total_bytes += subresource.first.spec().size();
-      total_bytes += sizeof(ReferrerValue);
-    }
-  }
-  UMA_HISTOGRAM_CUSTOM_COUNTS("Net.Predictor.Startup.DBSize", total_bytes, 1,
-                              10 * 1000 * 1000, 50);
-}
-
-
 // ---------------------- End IO methods. -------------------------------------
 
 //-----------------------------------------------------------------------------

chrome/browser/net/predictor.h

@@ -412,8 +412,6 @@ class Predictor {
   // Applies the HSTS redirect for |url|, if any.
   GURL GetHSTSRedirectOnIOThread(const GURL& url);
 
-  void LogStartupMetrics();
-
   // ------------- End IO thread methods.
 
   std::unique_ptr<InitialObserver> initial_observer_;

tools/metrics/histograms/histograms.xml

@@ -48298,6 +48298,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="Net.PreconnectMotivation" enum="PreconnectMotivation">
+  <obsolete>
+    Deprecated May 2018
+  </obsolete>
   <owner>csharrison@chromium.org</owner>
   <summary>
     When a preconnection is made, indicate what the motivation was.
@@ -48335,6 +48338,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="Net.PreconnectSubresourceEval"
     enum="PreconnectSubresourceEval">
+  <obsolete>
+    Deprecated May 2018
+  </obsolete>
   <owner>csharrison@chromium.org</owner>
   <summary>
     What did we decide to do about a predicted resource, based on the historical
@@ -48349,6 +48355,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="Net.PreconnectSubresourceExpectation">
+  <obsolete>
+    Deprecated May 2018
+  </obsolete>
   <owner>csharrison@chromium.org</owner>
   <summary>
     The expected number of connections, times 100, that we'll make to a given
@@ -48416,6 +48425,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </histogram>
 
 <histogram name="Net.Predictor.Startup.DBSize" units="bytes">
+  <obsolete>
+    Deprecated May 2018
+  </obsolete>
   <owner>csharrison@chromium.org</owner>
   <summary>
     The approximate size in bytes of the predictor's database on startup.