Remove PLT.* histograms.

chrome/renderer/page_load_histograms.cc

Index: chrome/renderer/page_load_histograms.cc
diff --git a/chrome/renderer/page_load_histograms.cc b/chrome/renderer/page_load_histograms.cc
deleted file mode 100644
index b7cbdff3890feff77172c60c9ee23d54e845f9c1..0000000000000000000000000000000000000000
--- a/chrome/renderer/page_load_histograms.cc
+++ /dev/null
@@ -1,630 +0,0 @@
-// 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.
-
-// TODO(bmcquade): delete this class in October 2016, as it is deprecated by the
-// new PageLoad.* UMA histograms.
-
-#include "chrome/renderer/page_load_histograms.h"
-
-#include <stddef.h>
-
-#include <memory>
-#include <string>
-
-#include "base/command_line.h"
-#include "base/logging.h"
-#include "base/metrics/field_trial.h"
-#include "base/metrics/histogram.h"
-#include "base/metrics/persistent_histogram_allocator.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/strings/string_split.h"
-#include "base/strings/string_util.h"
-#include "base/strings/stringprintf.h"
-#include "base/strings/utf_string_conversions.h"
-#include "base/time/time.h"
-#include "chrome/common/chrome_switches.h"
-#include "chrome/renderer/searchbox/search_bouncer.h"
-#include "content/public/common/content_constants.h"
-#include "content/public/renderer/document_state.h"
-#include "content/public/renderer/render_frame.h"
-#include "content/public/renderer/render_thread.h"
-#include "content/public/renderer/render_view.h"
-#include "extensions/common/url_pattern.h"
-#include "net/base/url_util.h"
-#include "net/http/http_response_headers.h"
-#include "third_party/WebKit/public/platform/URLConversion.h"
-#include "third_party/WebKit/public/platform/WebURLRequest.h"
-#include "third_party/WebKit/public/platform/WebURLResponse.h"
-#include "third_party/WebKit/public/web/WebDocument.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"
-
-#if defined(ENABLE_EXTENSIONS)
-#include "chrome/renderer/extensions/chrome_extensions_renderer_client.h"
-#include "extensions/renderer/dispatcher.h"
-#endif
-
-using blink::WebDataSource;
-using blink::WebLocalFrame;
-using blink::WebPerformance;
-using blink::WebString;
-using base::Time;
-using base::TimeDelta;
-using content::DocumentState;
-
-const size_t kPLTCount = 100;
-
-namespace {
-
-// ID indicating that no GWS-Chrome joint experiment is active.
-const int kNoExperiment = 0;
-
-// Max ID of GWS-Chrome joint experiment. If you change this value, please
-// update PLT_HISTOGRAM_WITH_GWS_VARIANT accordingly.
-const int kMaxExperimentID = 20;
-
-TimeDelta kPLTMin() {
-  return TimeDelta::FromMilliseconds(10);
-}
-TimeDelta kPLTMax() {
-  return TimeDelta::FromMinutes(10);
-}
-
-// This function corresponds to PLT_HISTOGRAM macro invocation without caching.
-// Use this for PLT histograms with dynamically generated names, which
-// otherwise can't use the caching PLT_HISTOGRAM macro without code duplication.
-void PltHistogramWithNoMacroCaching(const std::string& name,
-                                    const TimeDelta& sample) {
-  // The parameters should exacly match the parameters in
-  // UMA_HISTOGRAM_CUSTOM_TIMES macro.
-  base::HistogramBase* histogram_pointer = base::Histogram::FactoryTimeGet(
-      name, kPLTMin(), kPLTMax(), kPLTCount,
-      base::HistogramBase::kUmaTargetedHistogramFlag);
-  histogram_pointer->AddTime(sample);
-}
-
-// This records UMA corresponding to the PLT_HISTOGRAM macro without caching.
-void PltHistogramWithGwsPreview(const char* name,
-                                const TimeDelta& sample,
-                                bool is_preview,
-                                int experiment_id) {
-  std::string preview_suffix = is_preview ? "_Preview" : "_NoPreview";
-  PltHistogramWithNoMacroCaching(name + preview_suffix, sample);
-
-  if (experiment_id != kNoExperiment) {
-    std::string name_with_experiment_id = base::StringPrintf(
-          "%s%s_Experiment%d", name, preview_suffix.c_str(), experiment_id);
-    PltHistogramWithNoMacroCaching(name_with_experiment_id, sample);
-  }
-}
-
-#define PLT_HISTOGRAM(name, sample) \
-    UMA_HISTOGRAM_CUSTOM_TIMES(name, sample, kPLTMin(), kPLTMax(), kPLTCount);
-
-#define PLT_HISTOGRAM_WITH_GWS_VARIANT(                                        \
-    name, sample, came_from_websearch, websearch_chrome_joint_experiment_id,   \
-    is_preview) {                                                              \
-  PLT_HISTOGRAM(name, sample);                                                 \
-  if (came_from_websearch) {                                                   \
-    PLT_HISTOGRAM(base::StringPrintf("%s_FromGWS", name), sample)              \
-    if (websearch_chrome_joint_experiment_id != kNoExperiment) {               \
-      std::string name_with_experiment_id = base::StringPrintf(                \
-          "%s_FromGWS_Experiment%d",                                           \
-          name, websearch_chrome_joint_experiment_id);                         \
-      PltHistogramWithNoMacroCaching(name_with_experiment_id, sample);         \
-    }                                                                          \
-  }                                                                            \
-  PltHistogramWithGwsPreview(name, sample, is_preview,                         \
-                             websearch_chrome_joint_experiment_id);            \
-}
-
-// Returns the scheme type of the given URL if its type is one for which we
-// dump page load histograms. Otherwise returns NULL.
-URLPattern::SchemeMasks GetSupportedSchemeType(const GURL& url) {
-  if (url.SchemeIs("http"))
-    return URLPattern::SCHEME_HTTP;
-  else if (url.SchemeIs("https"))
-    return URLPattern::SCHEME_HTTPS;
-  return static_cast<URLPattern::SchemeMasks>(0);
-}
-
-// Helper function to check for string in 'via' header. Returns true if
-// |via_value| is one of the values listed in the Via header.
-bool ViaHeaderContains(WebLocalFrame* frame, const std::string& via_value) {
-  const char kViaHeaderName[] = "Via";
-  std::vector<std::string> values;
-  // Multiple via headers have already been coalesced and hence each value
-  // separated by a comma corresponds to a proxy. The value added by a proxy is
-  // not expected to contain any commas.
-  // Example., Via: 1.0 Compression proxy, 1.1 Google Instant Proxy Preview
-  values = base::SplitString(
-      frame->dataSource()->response().httpHeaderField(kViaHeaderName).utf8(),
-      ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
-  return std::find(values.begin(), values.end(), via_value) != values.end();
-}
-
-// Returns true if the provided URL is a referrer string that came from
-// a Google Web Search results page. This is a little non-deterministic
-// because desktop and mobile websearch differ and sometimes just provide
-// http://www.google.com/ as the referrer. In the case of /url we can be sure
-// that it came from websearch but we will be generous and allow for cases
-// where a non-Google URL was provided a bare Google URL as a referrer.
-// The domain validation matches the code used by the prerenderer for similar
-// purposes.
-// TODO(pmeenan): Remove the fuzzy logic when the referrer is reliable
-bool IsFromGoogleSearchResult(const GURL& url, const GURL& referrer) {
-  if (!base::StartsWith(referrer.host(), "www.google.",
-                        base::CompareCase::SENSITIVE))
-    return false;
-  if (base::StartsWith(referrer.path(), "/url",
-                       base::CompareCase::SENSITIVE))
-    return true;
-  bool is_possible_search_referrer =
-      referrer.path().empty() || referrer.path() == "/" ||
-      base::StartsWith(referrer.path(), "/search",
-                       base::CompareCase::SENSITIVE) ||
-      base::StartsWith(referrer.path(), "/webhp",
-                       base::CompareCase::SENSITIVE);
-  if (is_possible_search_referrer &&
-      !base::StartsWith(url.host(), "www.google",
-                        base::CompareCase::SENSITIVE))
-    return true;
-  return false;
-}
-
-// Extracts a Google Web Search and Chrome joint experiment ID from a referrer
-// that came from a Google Web Search results page. An experiment ID is embedded
-// in a query string as a "gcjeid=" parameter value.
-int GetQueryStringBasedExperiment(const GURL& referrer) {
-  std::string value;
-  if (!net::GetValueForKeyInQuery(referrer, "gcjeid", &value))
-    return kNoExperiment;
-
-  int experiment_id;
-  if (!base::StringToInt(value, &experiment_id))
-    return kNoExperiment;
-  if (0 < experiment_id && experiment_id <= kMaxExperimentID)
-    return experiment_id;
-  return kNoExperiment;
-}
-
-void DumpHistograms(const WebPerformance& performance,
-                    DocumentState* document_state,
-                    bool came_from_websearch,
-                    int websearch_chrome_joint_experiment_id,
-                    bool is_preview,
-                    URLPattern::SchemeMasks scheme_type) {
-  // This function records new histograms based on the Navigation Timing
-  // records. As such, the histograms should not depend on the deprecated timing
-  // information collected in DocumentState. However, here for some reason we
-  // check if document_state->request_time() is null. TODO(ppi): find out why
-  // and remove DocumentState from the parameter list.
-  Time request = document_state->request_time();
-
-  Time navigation_start = Time::FromDoubleT(performance.navigationStart());
-  Time request_start = Time::FromDoubleT(performance.requestStart());
-  Time response_start = Time::FromDoubleT(performance.responseStart());
-  Time dom_content_loaded_start =
-      Time::FromDoubleT(performance.domContentLoadedEventStart());
-  Time load_event_start = Time::FromDoubleT(performance.loadEventStart());
-  Time load_event_end = Time::FromDoubleT(performance.loadEventEnd());
-  Time begin = (request.is_null() ? navigation_start : request_start);
-
-  DCHECK(!navigation_start.is_null());
-
-  // It is possible for a document to have navigation_start time, but no
-  // request_start. An example is doing a window.open, which synchronously
-  // loads "about:blank", then using document.write add a meta http-equiv
-  // refresh tag, which causes a navigation. In such case, we will arrive at
-  // this function with no request/response timing data and identical load
-  // start/end values. Avoid logging this case, as it doesn't add any
-  // meaningful information to the histogram.
-  if (request_start.is_null())
-    return;
-
-  // TODO(dominich): Investigate conditions under which |load_event_start| and
-  // |load_event_end| may be NULL as in the non-PT_ case below. Examples in
-  // http://crbug.com/112006.
-  // DCHECK(!load_event_start.is_null());
-  // DCHECK(!load_event_end.is_null());
-
-  if (document_state->web_timing_histograms_recorded())
-    return;
-  document_state->set_web_timing_histograms_recorded(true);
-
-  // TODO(simonjam): There is no way to distinguish between abandonment and
-  // intentional Javascript navigation before the load event fires.
-  // TODO(dominich): Load type breakdown
-  if (!load_event_start.is_null()) {
-    PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_BeginToFinishDoc",
-                                   load_event_start - begin,
-                                   came_from_websearch,
-                                   websearch_chrome_joint_experiment_id,
-                                   is_preview);
-    PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_CommitToFinishDoc",
-                                   load_event_start - response_start,
-                                   came_from_websearch,
-                                   websearch_chrome_joint_experiment_id,
-                                   is_preview);
-    PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_RequestToFinishDoc",
-                                   load_event_start - navigation_start,
-                                   came_from_websearch,
-                                   websearch_chrome_joint_experiment_id,
-                                   is_preview);
-  }
-  if (!load_event_end.is_null()) {
-    PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_BeginToFinish",
-                                   load_event_end - begin,
-                                   came_from_websearch,
-                                   websearch_chrome_joint_experiment_id,
-                                   is_preview);
-    PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_CommitToFinish",
-                                   load_event_end - response_start,
-                                   came_from_websearch,
-                                   websearch_chrome_joint_experiment_id,
-                                   is_preview);
-    PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_RequestToFinish",
-                                   load_event_end - navigation_start,
-                                   came_from_websearch,
-                                   websearch_chrome_joint_experiment_id,
-                                   is_preview);
-    PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_StartToFinish",
-                                   load_event_end - request_start,
-                                   came_from_websearch,
-                                   websearch_chrome_joint_experiment_id,
-                                   is_preview);
-  }
-  if (!load_event_start.is_null() && !load_event_end.is_null()) {
-    PLT_HISTOGRAM("PLT.PT_FinishDocToFinish",
-                  load_event_end - load_event_start);
-  }
-  if (!dom_content_loaded_start.is_null()) {
-    PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_RequestToDomContentLoaded",
-                                   dom_content_loaded_start - navigation_start,
-                                   came_from_websearch,
-                                   websearch_chrome_joint_experiment_id,
-                                   is_preview);
-  }
-  PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_BeginToCommit",
-                                 response_start - begin,
-                                 came_from_websearch,
-                                 websearch_chrome_joint_experiment_id,
-                                 is_preview);
-  PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_RequestToStart",
-                                 request_start - navigation_start,
-                                 came_from_websearch,
-                                 websearch_chrome_joint_experiment_id,
-                                 is_preview);
-  PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_StartToCommit",
-                                 response_start - request_start,
-                                 came_from_websearch,
-                                 websearch_chrome_joint_experiment_id,
-                                 is_preview);
-  PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.PT_RequestToCommit",
-                                 response_start - navigation_start,
-                                 came_from_websearch,
-                                 websearch_chrome_joint_experiment_id,
-                                 is_preview);
-}
-
-bool WasWebRequestUsedBySomeExtensions() {
-#if defined(ENABLE_EXTENSIONS)
-  return ChromeExtensionsRendererClient::GetInstance()->extension_dispatcher()
-      ->WasWebRequestUsedBySomeExtensions();
-#else
-  return false;
-#endif
-}
-
-// These histograms are based on the timing information collected in
-// DocumentState. They should be transitioned to equivalents based on the
-// Navigation Timing records (see DumpPerformanceTiming()) or dropped if not
-// needed. Please do not add new metrics based on DocumentState.
-void DumpDeprecatedHistograms(const WebPerformance& performance,
-                              DocumentState* document_state,
-                              bool came_from_websearch,
-                              int websearch_chrome_joint_experiment_id,
-                              bool is_preview,
-                              URLPattern::SchemeMasks scheme_type) {
-  // If we've already dumped, do nothing.
-  // This simple bool works because we only dump for the main frame.
-  if (document_state->load_histograms_recorded())
-    return;
-
-  // Abort if any of these is missing.
-  Time start = document_state->start_load_time();
-  Time commit = document_state->commit_load_time();
-  Time navigation_start =
-      Time::FromDoubleT(performance.navigationStart());
-  if (start.is_null() || commit.is_null() || navigation_start.is_null())
-    return;
-
-  // We properly handle null values for the next 3 variables.
-  Time request = document_state->request_time();
-  Time first_paint = document_state->first_paint_time();
-  Time first_paint_after_load = document_state->first_paint_after_load_time();
-  Time finish_doc = document_state->finish_document_load_time();
-  Time finish_all_loads = document_state->finish_load_time();
-
-  // Handle case where user hits "stop" or "back" before loading completely.
-  // Note that this makes abandoned page loads be recorded as if they were
-  // completed, polluting the metrics with artifically short completion times.
-  // We are not fixing this as these metrics are being dropped as deprecated.
-  if (finish_doc.is_null()) {
-    finish_doc = Time::Now();
-    document_state->set_finish_document_load_time(finish_doc);
-  }
-  if (finish_all_loads.is_null()) {
-    finish_all_loads = Time::Now();
-    document_state->set_finish_load_time(finish_all_loads);
-  }
-
-  document_state->set_load_histograms_recorded(true);
-
-  // Note: Client side redirects will have no request time.
-  Time begin = request.is_null() ? start : request;
-  TimeDelta begin_to_finish_doc = finish_doc - begin;
-  TimeDelta begin_to_finish_all_loads = finish_all_loads - begin;
-  TimeDelta start_to_finish_all_loads = finish_all_loads - start;
-  TimeDelta start_to_commit = commit - start;
-
-  DocumentState::LoadType load_type = document_state->load_type();
-
-  // The above code sanitized all values of times, in preparation for creating
-  // actual histograms.  The remainder of this code could be run at destructor
-  // time for the document_state, since all data is intact.
-
-  // Aggregate PLT data across all link types.
-  UMA_HISTOGRAM_ENUMERATION("PLT.LoadType", load_type,
-      DocumentState::kLoadTypeMax);
-  PLT_HISTOGRAM("PLT.StartToCommit", start_to_commit);
-  PLT_HISTOGRAM("PLT.CommitToFinishDoc", finish_doc - commit);
-  PLT_HISTOGRAM("PLT.FinishDocToFinish", finish_all_loads - finish_doc);
-  PLT_HISTOGRAM("PLT.BeginToCommit", commit - begin);
-  PLT_HISTOGRAM("PLT.StartToFinish", start_to_finish_all_loads);
-  if (!request.is_null()) {
-    PLT_HISTOGRAM("PLT.RequestToStart", start - request);
-    PLT_HISTOGRAM("PLT.RequestToFinish", finish_all_loads - request);
-  }
-  PLT_HISTOGRAM("PLT.CommitToFinish", finish_all_loads - commit);
-
-  std::unique_ptr<TimeDelta> begin_to_first_paint;
-  std::unique_ptr<TimeDelta> commit_to_first_paint;
-  if (!first_paint.is_null()) {
-    // 'first_paint' can be before 'begin' for an unknown reason.
-    // See bug http://crbug.com/125273 for details.
-    if (begin <= first_paint) {
-      begin_to_first_paint.reset(new TimeDelta(first_paint - begin));
-      PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.BeginToFirstPaint",
-                                     *begin_to_first_paint,
-                                     came_from_websearch,
-                                     websearch_chrome_joint_experiment_id,
-                                     is_preview);
-    } else {
-      // Track the frequency and magnitude of cases where first_paint precedes
-      // begin. The current hypothesis is that this is due to using the
-      // non-monotonic timer. If that's the case, we expect first_paint
-      // preceding begin to be rare, and the delta between values to be close to
-      // zero. This is a temporary addition that we will remove once we better
-      // understand the frequency and magnitude of first_paint preceding begin.
-      PLT_HISTOGRAM("PLT.BeginToFirstPaint_Negative", begin - first_paint);
-    }
-
-    // Conditional was previously a DCHECK. Changed due to multiple bot
-    // failures, listed in crbug.com/383963
-    if (commit <= first_paint) {
-      commit_to_first_paint.reset(new TimeDelta(first_paint - commit));
-      PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.CommitToFirstPaint",
-                                     *commit_to_first_paint,
-                                     came_from_websearch,
-                                     websearch_chrome_joint_experiment_id,
-                                     is_preview);
-    }
-  }
-  if (!first_paint_after_load.is_null()) {
-    // 'first_paint_after_load' can be before 'begin' for an unknown reason.
-    // See bug http://crbug.com/125273 for details.
-    if (begin <= first_paint_after_load) {
-      PLT_HISTOGRAM("PLT.BeginToFirstPaintAfterLoad",
-          first_paint_after_load - begin);
-    }
-    // Both following conditionals were previously DCHECKs. Changed due to
-    // multiple bot failures, listed in crbug.com/383963
-    if (commit <= first_paint_after_load) {
-      PLT_HISTOGRAM("PLT.CommitToFirstPaintAfterLoad",
-          first_paint_after_load - commit);
-    }
-    if (finish_all_loads <= first_paint_after_load) {
-      PLT_HISTOGRAM("PLT.FinishToFirstPaintAfterLoad",
-          first_paint_after_load - finish_all_loads);
-    }
-  }
-  PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.BeginToFinishDoc", begin_to_finish_doc,
-                                 came_from_websearch,
-                                 websearch_chrome_joint_experiment_id,
-                                 is_preview);
-  PLT_HISTOGRAM_WITH_GWS_VARIANT("PLT.BeginToFinish", begin_to_finish_all_loads,
-                                 came_from_websearch,
-                                 websearch_chrome_joint_experiment_id,
-                                 is_preview);
-
-  // Load type related histograms.
-  switch (load_type) {
-    case DocumentState::UNDEFINED_LOAD:
-      PLT_HISTOGRAM("PLT.BeginToFinishDoc_UndefLoad", begin_to_finish_doc);
-      PLT_HISTOGRAM("PLT.BeginToFinish_UndefLoad", begin_to_finish_all_loads);
-      break;
-    case DocumentState::RELOAD:
-      PLT_HISTOGRAM("PLT.BeginToFinishDoc_Reload", begin_to_finish_doc);
-      PLT_HISTOGRAM("PLT.BeginToFinish_Reload", begin_to_finish_all_loads);
-      break;
-    case DocumentState::HISTORY_LOAD:
-      PLT_HISTOGRAM("PLT.BeginToFinishDoc_HistoryLoad", begin_to_finish_doc);
-      PLT_HISTOGRAM("PLT.BeginToFinish_HistoryLoad", begin_to_finish_all_loads);
-      break;
-    case DocumentState::NORMAL_LOAD:
-      PLT_HISTOGRAM("PLT.BeginToFinishDoc_NormalLoad", begin_to_finish_doc);
-      PLT_HISTOGRAM("PLT.BeginToFinish_NormalLoad", begin_to_finish_all_loads);
-      break;
-    case DocumentState::LINK_LOAD_NORMAL:
-      PLT_HISTOGRAM("PLT.BeginToFinishDoc_LinkLoadNormal",
-          begin_to_finish_doc);
-      PLT_HISTOGRAM("PLT.BeginToFinish_LinkLoadNormal",
-                    begin_to_finish_all_loads);
-      break;
-    case DocumentState::LINK_LOAD_RELOAD:
-      PLT_HISTOGRAM("PLT.BeginToFinishDoc_LinkLoadReload",
-           begin_to_finish_doc);
-      PLT_HISTOGRAM("PLT.BeginToFinish_LinkLoadReload",
-                    begin_to_finish_all_loads);
-      break;
-    case DocumentState::LINK_LOAD_CACHE_STALE_OK:
-      PLT_HISTOGRAM("PLT.BeginToFinishDoc_LinkLoadStaleOk",
-           begin_to_finish_doc);
-      PLT_HISTOGRAM("PLT.BeginToFinish_LinkLoadStaleOk",
-                    begin_to_finish_all_loads);
-      break;
-    case DocumentState::LINK_LOAD_CACHE_ONLY:
-      PLT_HISTOGRAM("PLT.BeginToFinishDoc_LinkLoadCacheOnly",
-           begin_to_finish_doc);
-      PLT_HISTOGRAM("PLT.BeginToFinish_LinkLoadCacheOnly",
-                    begin_to_finish_all_loads);
-      break;
-    default:
-      break;
-  }
-
-  const bool use_webrequest_histogram = WasWebRequestUsedBySomeExtensions();
-  if (use_webrequest_histogram) {
-    switch (load_type) {
-      case DocumentState::NORMAL_LOAD:
-        PLT_HISTOGRAM(
-            "PLT.BeginToFinish_NormalLoad_ExtensionWebRequest",
-            begin_to_finish_all_loads);
-        break;
-      case DocumentState::LINK_LOAD_NORMAL:
-        PLT_HISTOGRAM(
-            "PLT.BeginToFinish_LinkLoadNormal_ExtensionWebRequest",
-            begin_to_finish_all_loads);
-        break;
-      case DocumentState::LINK_LOAD_RELOAD:
-        PLT_HISTOGRAM(
-            "PLT.BeginToFinish_LinkLoadReload_ExtensionWebRequest",
-            begin_to_finish_all_loads);
-        break;
-      case DocumentState::LINK_LOAD_CACHE_STALE_OK:
-        PLT_HISTOGRAM(
-            "PLT.BeginToFinish_LinkLoadStaleOk_ExtensionWebRequest",
-            begin_to_finish_all_loads);
-        break;
-      default:
-        break;
-    }
-  }
-}
-
-}  // namespace
-
-PageLoadHistograms::PageLoadHistograms(content::RenderFrame* render_frame)
-    : content::RenderFrameObserver(render_frame), helper_(this) {}
-
-PageLoadHistograms::~PageLoadHistograms() {
-}
-
-void PageLoadHistograms::Dump() {
-  WebLocalFrame* frame = render_frame()->GetWebFrame();
-
-  // We only dump histograms for main frames.
-  // In the future, it may be interesting to tag subframes and dump them too.
-  DCHECK(frame && !frame->parent());
-
-  // Only dump for supported schemes.
-  URLPattern::SchemeMasks scheme_type =
-      GetSupportedSchemeType(frame->document().url());
-  if (scheme_type == 0)
-    return;
-
-  // Don't dump stats for the NTP, as PageLoadHistograms should only be recorded
-  // for pages visited due to an explicit user navigation.
-  if (SearchBouncer::GetInstance()->IsNewTabPage(frame->document().url())) {
-    return;
-  }
-
-  DocumentState* document_state =
-      DocumentState::FromDataSource(frame->dataSource());
-
-  bool came_from_websearch = IsFromGoogleSearchResult(
-      frame->document().url(),
-      blink::WebStringToGURL(frame->document().referrer()));
-  int websearch_chrome_joint_experiment_id = kNoExperiment;
-  bool is_preview = false;
-  if (came_from_websearch) {
-    websearch_chrome_joint_experiment_id = GetQueryStringBasedExperiment(
-        blink::WebStringToGURL(frame->document().referrer()));
-    is_preview = ViaHeaderContains(frame, "1.1 Google Instant Proxy Preview");
-  }
-
-  // Metrics based on the timing information recorded for the Navigation Timing
-  // API - http://www.w3.org/TR/navigation-timing/.
-  DumpHistograms(frame->performance(), document_state, came_from_websearch,
-                 websearch_chrome_joint_experiment_id, is_preview, scheme_type);
-
-  // Old metrics based on the timing information stored in DocumentState. These
-  // are deprecated and should go away.
-  DumpDeprecatedHistograms(
-      frame->performance(), document_state, came_from_websearch,
-      websearch_chrome_joint_experiment_id, is_preview, scheme_type);
-
-  // Log the PLT to the info log.
-  LogPageLoadTime(document_state, frame->dataSource());
-
-  // If persistent histograms are not enabled, initiate a PostTask here to be
-  // sure that we send the histograms generated. Without this call, pages
-  // that don't have an on-close-handler might generate data that is lost if
-  // the renderer is shutdown abruptly (e.g. the user closed the tab).
-  // TODO(bcwhite): Remove completely when persistence is on-by-default.
-  if (!base::GlobalHistogramAllocator::Get()) {
-    content::RenderThread::Get()->UpdateHistograms(
-        content::kHistogramSynchronizerReservedSequenceNumber);
-  }
-}
-
-void PageLoadHistograms::WillCommitProvisionalLoad() {
-  Dump();
-}
-
-void PageLoadHistograms::LogPageLoadTime(const DocumentState* document_state,
-                                         const WebDataSource* ds) const {
-  // Because this function gets called on every page load,
-  // take extra care to optimize it away if logging is turned off.
-  if (logging::LOG_INFO < logging::GetMinLogLevel())
-    return;
-
-  DCHECK(document_state);
-  DCHECK(ds);
-  GURL url(ds->request().url());
-  Time start = document_state->start_load_time();
-  Time finish = document_state->finish_load_time();
-  // TODO(mbelshe): should we log more stats?
-  VLOG(1) << "PLT: " << (finish - start).InMilliseconds() << "ms "
-          << url.spec();
-}
-
-void PageLoadHistograms::OnDestruct() {
-  delete this;
-}
-
-PageLoadHistograms::Helper::Helper(PageLoadHistograms* histograms)
-    : RenderViewObserver(histograms->render_frame()->GetRenderView()),
-      histograms_(histograms) {
-}
-
-void PageLoadHistograms::Helper::ClosePage() {
-  histograms_->Dump();
-}
-
-void PageLoadHistograms::Helper::OnDestruct() {
-}