Delete mod_pagespeed code and metrics

These metrics are not tracked, and the code is not really being
maintained.

Bug: None
Change-Id: I030919ac8a2cf4e744ed120cdbcab282dcc6aea1
Reviewed-on: https://chromium-review.googlesource.com/1027800
Commit-Queue: Charlie Harrison <csharrison@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Egor Pasko <pasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553761}

chrome/browser/BUILD.gn

@@ -726,8 +726,6 @@ jumbo_split_static_library("browser") {
     "metrics/thread_watcher_report_hang.h",
     "metrics/variations/chrome_variations_service_client.cc",
     "metrics/variations/chrome_variations_service_client.h",
-    "mod_pagespeed/mod_pagespeed_metrics.cc",
-    "mod_pagespeed/mod_pagespeed_metrics.h",
     "native_window_notification_source.h",
     "net/chrome_accept_language_settings.cc",
     "net/chrome_accept_language_settings.h",

chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc

@@ -26,7 +26,6 @@
 #include "chrome/browser/loader/chrome_navigation_data.h"
 #include "chrome/browser/loader/predictor_resource_throttle.h"
 #include "chrome/browser/loader/safe_browsing_resource_throttle.h"
-#include "chrome/browser/mod_pagespeed/mod_pagespeed_metrics.h"
 #include "chrome/browser/net/loading_predictor_observer.h"
 #include "chrome/browser/page_load_metrics/metrics_web_contents_observer.h"
 #include "chrome/browser/plugins/plugin_prefs.h"
@@ -695,9 +694,6 @@ void ChromeResourceDispatcherHostDelegate::OnResponseStarted(
       LogCommittedPreviewsDecision(io_data, request->url(), previews_user_data);
     }
   }
-
-  mod_pagespeed::RecordMetrics(info->GetResourceType(), request->url(),
-                               request->response_headers());
 }
 
 void ChromeResourceDispatcherHostDelegate::OnRequestRedirected(

chrome/browser/mod_pagespeed/OWNERS

-csharrison@chromium.org

chrome/browser/mod_pagespeed/mod_pagespeed_metrics.cc

-// Copyright 2015 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/mod_pagespeed/mod_pagespeed_metrics.h"
-
-#include <stdio.h>
-
-#include <string>
-
-#include "base/metrics/histogram_functions.h"
-#include "base/metrics/histogram_macros.h"
-#include "net/http/http_response_headers.h"
-#include "url/gurl.h"
-
-namespace mod_pagespeed {
-
-namespace {
-
-const char kModPagespeedHeader[] = "X-Mod-Pagespeed";
-const char kPageSpeedHeader[] = "X-Page-Speed";
-
-// For historical reasons, mod_pagespeed usage metrics are named with a
-// prerender prefix.
-const char kPagespeedServerHistogram[] =
-    "Prerender.PagespeedHeader.ServerCounts";
-const char kPagespeedVersionHistogram[] =
-    "Prerender.PagespeedHeader.VersionCounts";
-
-enum PagespeedHeaderServerType {
-  PAGESPEED_TOTAL_RESPONSES = 0,
-  PAGESPEED_MOD_PAGESPEED_SERVER = 1,
-  PAGESPEED_NGX_PAGESPEED_SERVER = 2,
-  PAGESPEED_PAGESPEED_SERVICE_SERVER = 3,
-  PAGESPEED_UNKNOWN_SERVER = 4,
-  PAGESPEED_SERVER_MAXIMUM = 5
-};
-
-// Parse the PageSpeed version number and encodes it in buckets 2 through 99: if
-// it is in the format MAJOR.MINOR.BRANCH.POINT-COMMIT the bucket will be 2 + 2
-// * (max(BRANCH, 10) - 10) + (POINT > 1 ? 1 : 0); otherwise the bucket is
-// zero.
-int GetXModPagespeedBucketFromVersion(const std::string& version) {
-  int unused_major, unused_minor, branch, point, unused_commit;
-  int num_parsed = sscanf(version.c_str(), "%d.%d.%d.%d-%d", &unused_major,
-                          &unused_minor, &branch, &point, &unused_commit);
-  int output = 0;
-  if (num_parsed >= 4) {
-    output = 2;
-    if (branch > 10)
-      output += 2 * (branch - 10);
-    if (point > 1)
-      output++;
-    if (output < 2 || output > 99)
-      output = 0;
-  }
-  return output;
-}
-
-// Parse the X-Page-Speed header value and determine whether it is in the
-// PageSpeed Service format, namely MAJOR_MINOR_AB were MAJOR_MINOR is a version
-// number and AB is an encoded 2-character value.
-bool IsPageSpeedServiceVersionNumber(const std::string& version) {
-  int major, minor;
-  // is_eol is to detect EOL as we check that it /isn't/ converted.
-  char a, b, is_eol;
-  int num_parsed =
-      sscanf(version.c_str(), "%d_%d_%c%c%c", &major, &minor, &a, &b, &is_eol);
-  return (num_parsed == 4);
-}
-
-}  // namespace
-
-void RecordMetrics(const content::ResourceType resource_type,
-                   const GURL& request_url,
-                   const net::HttpResponseHeaders* response_headers) {
-  if (resource_type != content::RESOURCE_TYPE_MAIN_FRAME ||
-      !request_url.SchemeIsHTTPOrHTTPS()) {
-    return;
-  }
-
-  // Bucket 0 counts every response seen.
-  UMA_HISTOGRAM_ENUMERATION(kPagespeedServerHistogram,
-                            PAGESPEED_TOTAL_RESPONSES,
-                            PAGESPEED_SERVER_MAXIMUM);
-  if (!response_headers)
-    return;
-
-  size_t iter = 0;
-  std::string name;
-  std::string value;
-  while (response_headers->EnumerateHeaderLines(&iter, &name, &value)) {
-    if (name == kModPagespeedHeader) {
-      // Bucket 1 counts occurrences of the X-Mod-Pagespeed header.
-      UMA_HISTOGRAM_ENUMERATION(kPagespeedServerHistogram,
-                                PAGESPEED_MOD_PAGESPEED_SERVER,
-                                PAGESPEED_SERVER_MAXIMUM);
-      if (!value.empty()) {
-        // If the header value is in the X-Mod-Pagespeed version number format
-        // then increment the appropriate bucket, otherwise increment bucket 1,
-        // which is the catch-all "unknown version number" bucket.
-        int bucket = GetXModPagespeedBucketFromVersion(value);
-        if (bucket > 0) {
-          base::UmaHistogramSparse(kPagespeedVersionHistogram, bucket);
-        } else {
-          base::UmaHistogramSparse(kPagespeedVersionHistogram, 1);
-        }
-      }
-      break;
-    } else if (name == kPageSpeedHeader) {
-      // X-Page-Speed header versions are either in the X-Mod-Pagespeed format,
-      // indicating an nginx installation, or they're in the PageSpeed Service
-      // format, indicating a PSS installation, or in some other format,
-      // indicating an unknown installation [possibly IISpeed].
-      if (!value.empty()) {
-        int bucket = GetXModPagespeedBucketFromVersion(value);
-        if (bucket > 0) {
-          // Bucket 2 counts occurences of the X-Page-Speed header with a
-          // value in the X-Mod-Pagespeed version number format. We also
-          // count these responses in the version histogram.
-          UMA_HISTOGRAM_ENUMERATION(kPagespeedServerHistogram,
-                                    PAGESPEED_NGX_PAGESPEED_SERVER,
-                                    PAGESPEED_SERVER_MAXIMUM);
-          base::UmaHistogramSparse(kPagespeedVersionHistogram, bucket);
-        } else if (IsPageSpeedServiceVersionNumber(value)) {
-          // Bucket 3 counts occurences of the X-Page-Speed header with a
-          // value in the PageSpeed Service version number format.
-          UMA_HISTOGRAM_ENUMERATION(kPagespeedServerHistogram,
-                                    PAGESPEED_PAGESPEED_SERVICE_SERVER,
-                                    PAGESPEED_SERVER_MAXIMUM);
-        } else {
-          // Bucket 4 counts occurences of all other values.
-          UMA_HISTOGRAM_ENUMERATION(kPagespeedServerHistogram,
-                                    PAGESPEED_UNKNOWN_SERVER,
-                                    PAGESPEED_SERVER_MAXIMUM);
-        }
-      }
-      break;
-    }
-  }
-}
-
-}  // namespace mod_pagespeed

chrome/browser/mod_pagespeed/mod_pagespeed_metrics.h

-// Copyright 2015 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.
-
-#ifndef CHROME_BROWSER_MOD_PAGESPEED_MOD_PAGESPEED_METRICS_H_
-#define CHROME_BROWSER_MOD_PAGESPEED_MOD_PAGESPEED_METRICS_H_
-
-#include "content/public/common/resource_type.h"
-
-class GURL;
-
-namespace net {
-class HttpResponseHeaders;
-}
-
-namespace mod_pagespeed {
-
-// Records metrics about mod_pagespeed headers.
-//
-// See
-// https://developers.google.com/speed/pagespeed/module/configuration#XHeaderValue
-void RecordMetrics(const content::ResourceType resource_type,
-                   const GURL& request_url,
-                   const net::HttpResponseHeaders* response_headers);
-
-}  // namespace mod_pagespeed
-
-#endif  // CHROME_BROWSER_MOD_PAGESPEED_MOD_PAGESPEED_METRICS_H_

chrome/browser/mod_pagespeed/mod_pagespeed_metrics_unittest.cc

-// Copyright 2015 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/mod_pagespeed/mod_pagespeed_metrics.h"
-
-#include <algorithm>
-#include <memory>
-#include <string>
-
-#include "base/memory/ref_counted.h"
-#include "base/metrics/histogram_macros.h"
-#include "base/metrics/histogram_samples.h"
-#include "base/metrics/statistics_recorder.h"
-#include "content/public/common/resource_type.h"
-#include "net/http/http_response_headers.h"
-#include "testing/gtest/include/gtest/gtest.h"
-#include "url/gurl.h"
-
-namespace mod_pagespeed {
-
-// Ensure that we count PageSpeed headers correctly.
-TEST(ModPagespeedMetricsTest, CountPageSpeedHeadersTest) {
-  GURL url("http://google.com");
-  std::string temp("HTTP/1.1 200 OK\n\n");
-  std::replace(temp.begin(), temp.end(), '\n', '\0');
-  scoped_refptr<net::HttpResponseHeaders> headers(
-      new net::HttpResponseHeaders(temp));
-
-  int num_responses = 0;
-  int num_mps = 0;
-  int num_ngx = 0;
-  int num_pss = 0;
-  int num_other = 0;
-  int num_bucket_1 = 0;   // unrecognized format/value bucket
-  int num_bucket_30 = 0;  // 1.2.24.1 bucket
-  int num_bucket_33 = 0;  // 1.3.25.2 bucket
-
-  std::unique_ptr<base::HistogramSamples> server_samples;
-  std::unique_ptr<base::HistogramSamples> version_samples;
-
-  // No PageSpeed header. The VersionCounts histogram isn't created yet.
-  RecordMetrics(content::RESOURCE_TYPE_MAIN_FRAME, url, headers.get());
-  base::HistogramBase* server_histogram =
-      base::StatisticsRecorder::FindHistogram(
-          "Prerender.PagespeedHeader.ServerCounts");
-  ASSERT_TRUE(server_histogram != NULL);
-  ASSERT_TRUE(NULL == base::StatisticsRecorder::FindHistogram(
-                          "Prerender.PagespeedHeader.VersionCounts"));
-
-  server_samples = server_histogram->SnapshotSamples();
-  EXPECT_EQ(++num_responses, server_samples->GetCount(0));
-  EXPECT_EQ(num_mps, server_samples->GetCount(1));
-  EXPECT_EQ(num_ngx, server_samples->GetCount(2));
-  EXPECT_EQ(num_pss, server_samples->GetCount(3));
-  EXPECT_EQ(num_other, server_samples->GetCount(4));
-
-  // X-Mod-Pagespeed header in expected format. VersionCounts now exists.
-  headers->AddHeader("X-Mod-Pagespeed: 1.2.24.1-2300");
-  RecordMetrics(content::RESOURCE_TYPE_MAIN_FRAME, url, headers.get());
-  base::HistogramBase* version_histogram =
-      base::StatisticsRecorder::FindHistogram(
-          "Prerender.PagespeedHeader.VersionCounts");
-  ASSERT_TRUE(version_histogram != NULL);
-  server_samples = server_histogram->SnapshotSamples();
-  version_samples = version_histogram->SnapshotSamples();
-  EXPECT_EQ(++num_responses, server_samples->GetCount(0));
-  EXPECT_EQ(++num_mps, server_samples->GetCount(1));
-  EXPECT_EQ(num_ngx, server_samples->GetCount(2));
-  EXPECT_EQ(num_pss, server_samples->GetCount(3));
-  EXPECT_EQ(num_other, server_samples->GetCount(4));
-  EXPECT_EQ(num_bucket_1, version_samples->GetCount(1));
-  EXPECT_EQ(++num_bucket_30, version_samples->GetCount(30));  // +1 for #30
-  EXPECT_EQ(num_bucket_33, version_samples->GetCount(33));
-  headers->RemoveHeader("X-Mod-Pagespeed");
-
-  // X-Mod-Pagespeed header in expected format, without (optional) SVN commit
-  // number.
-  headers->AddHeader("X-Mod-Pagespeed: 1.2.24.1");
-  RecordMetrics(content::RESOURCE_TYPE_MAIN_FRAME, url, headers.get());
-  server_samples = server_histogram->SnapshotSamples();
-  version_samples = version_histogram->SnapshotSamples();
-  EXPECT_EQ(++num_responses, server_samples->GetCount(0));
-  EXPECT_EQ(++num_mps, server_samples->GetCount(1));
-  EXPECT_EQ(num_ngx, server_samples->GetCount(2));
-  EXPECT_EQ(num_pss, server_samples->GetCount(3));
-  EXPECT_EQ(num_other, server_samples->GetCount(4));
-  EXPECT_EQ(num_bucket_1, version_samples->GetCount(1));
-  EXPECT_EQ(++num_bucket_30, version_samples->GetCount(30));  // +1 for #30
-  EXPECT_EQ(num_bucket_33, version_samples->GetCount(33));
-  headers->RemoveHeader("X-Mod-Pagespeed");
-
-  // X-Mod-Pagespeed header in unexpected format.
-  headers->AddHeader("X-Mod-Pagespeed: Powered By PageSpeed!");
-  RecordMetrics(content::RESOURCE_TYPE_MAIN_FRAME, url, headers.get());
-  server_samples = server_histogram->SnapshotSamples();
-  version_samples = version_histogram->SnapshotSamples();
-  EXPECT_EQ(++num_responses, server_samples->GetCount(0));
-  EXPECT_EQ(++num_mps, server_samples->GetCount(1));
-  EXPECT_EQ(num_ngx, server_samples->GetCount(2));
-  EXPECT_EQ(num_pss, server_samples->GetCount(3));
-  EXPECT_EQ(num_other, server_samples->GetCount(4));
-  EXPECT_EQ(++num_bucket_1, version_samples->GetCount(1));  // +1 for 'huh?'
-  EXPECT_EQ(num_bucket_30, version_samples->GetCount(30));
-  EXPECT_EQ(num_bucket_33, version_samples->GetCount(33));
-  headers->RemoveHeader("X-Mod-Pagespeed");
-
-  // X-Page-Speed header in mod_pagespeed format (so ngx_pagespeed).
-  headers->AddHeader("X-Page-Speed: 1.3.25.2-2530");
-  RecordMetrics(content::RESOURCE_TYPE_MAIN_FRAME, url, headers.get());
-  server_samples = server_histogram->SnapshotSamples();
-  version_samples = version_histogram->SnapshotSamples();
-  EXPECT_EQ(++num_responses, server_samples->GetCount(0));
-  EXPECT_EQ(num_mps, server_samples->GetCount(1));
-  EXPECT_EQ(++num_ngx, server_samples->GetCount(2));
-  EXPECT_EQ(num_pss, server_samples->GetCount(3));
-  EXPECT_EQ(num_other, server_samples->GetCount(4));
-  EXPECT_EQ(num_bucket_1, version_samples->GetCount(1));
-  EXPECT_EQ(num_bucket_30, version_samples->GetCount(30));
-  EXPECT_EQ(++num_bucket_33, version_samples->GetCount(33));  // +1 for #33
-  headers->RemoveHeader("X-Page-Speed");
-
-  // X-Page-Speed header in PageSpeed Service format.
-  headers->AddHeader("X-Page-Speed: 97_4_bo");
-  RecordMetrics(content::RESOURCE_TYPE_MAIN_FRAME, url, headers.get());
-  server_samples = server_histogram->SnapshotSamples();
-  version_samples = version_histogram->SnapshotSamples();
-  EXPECT_EQ(++num_responses, server_samples->GetCount(0));
-  EXPECT_EQ(num_mps, server_samples->GetCount(1));  // no change
-  EXPECT_EQ(num_ngx, server_samples->GetCount(2));
-  EXPECT_EQ(++num_pss, server_samples->GetCount(3));  // +1 for PSS
-  EXPECT_EQ(num_other, server_samples->GetCount(4));
-  EXPECT_EQ(num_bucket_1, version_samples->GetCount(1));
-  EXPECT_EQ(num_bucket_30, version_samples->GetCount(30));
-  EXPECT_EQ(num_bucket_33, version_samples->GetCount(33));
-  headers->RemoveHeader("X-Page-Speed");
-
-  // X-Page-Speed header in an unrecognized format (IISpeed in this case).
-  headers->AddHeader("X-Page-Speed: 1.0PS1.2-20130615");
-  RecordMetrics(content::RESOURCE_TYPE_MAIN_FRAME, url, headers.get());
-  server_samples = server_histogram->SnapshotSamples();
-  version_samples = version_histogram->SnapshotSamples();
-  EXPECT_EQ(++num_responses, server_samples->GetCount(0));
-  EXPECT_EQ(num_mps, server_samples->GetCount(1));  // no change
-  EXPECT_EQ(num_pss, server_samples->GetCount(3));
-  EXPECT_EQ(++num_other, server_samples->GetCount(4));  // +1 for 'other'
-  EXPECT_EQ(num_bucket_1, version_samples->GetCount(1));
-  EXPECT_EQ(num_bucket_30, version_samples->GetCount(30));
-  EXPECT_EQ(num_bucket_33, version_samples->GetCount(33));
-
-  // Not a main frame => not counted at all.
-  RecordMetrics(content::RESOURCE_TYPE_SUB_FRAME, url, headers.get());
-  server_samples = server_histogram->SnapshotSamples();
-  version_samples = version_histogram->SnapshotSamples();
-  EXPECT_EQ(num_responses, server_samples->GetCount(0));
-  EXPECT_EQ(num_mps, server_samples->GetCount(1));
-  EXPECT_EQ(num_ngx, server_samples->GetCount(2));
-  EXPECT_EQ(num_pss, server_samples->GetCount(3));
-  EXPECT_EQ(num_other, server_samples->GetCount(4));
-  EXPECT_EQ(num_bucket_1, version_samples->GetCount(1));
-  EXPECT_EQ(num_bucket_30, version_samples->GetCount(30));
-  EXPECT_EQ(num_bucket_33, version_samples->GetCount(33));
-
-  // Not a http/https URL => not counted at all.
-  GURL data_url("data:image/png;base64,yadda yadda==");
-  RecordMetrics(content::RESOURCE_TYPE_MAIN_FRAME, data_url, headers.get());
-  server_samples = server_histogram->SnapshotSamples();
-  version_samples = version_histogram->SnapshotSamples();
-  EXPECT_EQ(num_responses, server_samples->GetCount(0));
-  EXPECT_EQ(num_mps, server_samples->GetCount(1));
-  EXPECT_EQ(num_ngx, server_samples->GetCount(2));
-  EXPECT_EQ(num_pss, server_samples->GetCount(3));
-  EXPECT_EQ(num_other, server_samples->GetCount(4));
-  EXPECT_EQ(num_bucket_1, version_samples->GetCount(1));
-  EXPECT_EQ(num_bucket_30, version_samples->GetCount(30));
-  EXPECT_EQ(num_bucket_33, version_samples->GetCount(33));
-
-  headers->RemoveHeader("X-Page-Speed");
-}
-
-}  // namespace mod_pagespeed

chrome/test/BUILD.gn

@@ -2410,7 +2410,6 @@ test("unit_tests") {
     "../browser/metrics/subprocess_metrics_provider_unittest.cc",
     "../browser/metrics/thread_watcher_android_unittest.cc",
     "../browser/metrics/thread_watcher_unittest.cc",
-    "../browser/mod_pagespeed/mod_pagespeed_metrics_unittest.cc",
     "../browser/net/chrome_accept_language_settings_unittest.cc",
     "../browser/net/chrome_network_delegate_unittest.cc",
     "../browser/net/dns_probe_runner_unittest.cc",

tools/metrics/histograms/enums.xml

@@ -34208,6 +34208,9 @@ Called by update_net_trust_anchors.py.-->
 </enum>
 
 <enum name="PagespeedHeaderServerType">
+  <obsolete>
+    Deprecated April 2018
+  </obsolete>
   <int value="0" label="Total responses"/>
   <int value="1" label="mod_pagespeed server"/>
   <int value="2" label="ngx_pagespeed server"/>
@@ -34216,6 +34219,9 @@ Called by update_net_trust_anchors.py.-->
 </enum>
 
 <enum name="PagespeedVersion">
+  <obsolete>
+    Deprecated April 2018
+  </obsolete>
   <summary>
     The version of PageSpeed. Values up to 1.6.29.x are in use as of 2013-10-01
     while later values may adjust 'a' and/or 'b' arbitrarily.

tools/metrics/histograms/histograms.xml

@@ -71187,6 +71187,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="Prerender.PagespeedHeader.ServerCounts"
     enum="PagespeedHeaderServerType">
+  <obsolete>
+    Deprecated April 2018
+  </obsolete>
   <owner>pasko@chromium.org</owner>
   <summary>
     The number of responses received bucketed into the range [0,4]: bucket 0 is
@@ -71205,6 +71208,9 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 
 <histogram name="Prerender.PagespeedHeader.VersionCounts"
     enum="PagespeedVersion">
+  <obsolete>
+    Deprecated April 2018
+  </obsolete>
   <owner>pasko@chromium.org</owner>
   <summary>
     The number of responses received that either have an X-Mod-Pagespeed header