Adding AMP cache PageLoad.* metrics

chrome/browser/page_load_metrics/observers/amp_page_load_metrics_observer.cc

Index: chrome/browser/page_load_metrics/observers/amp_page_load_metrics_observer.cc
diff --git a/chrome/browser/page_load_metrics/observers/amp_page_load_metrics_observer.cc b/chrome/browser/page_load_metrics/observers/amp_page_load_metrics_observer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e9a6384f38d63be23d202e661287c3cc8e5d3167
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+++ b/chrome/browser/page_load_metrics/observers/amp_page_load_metrics_observer.cc
@@ -0,0 +1,113 @@
+// Copyright 2016 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/page_load_metrics/observers/amp_page_load_metrics_observer.h"
+
+#include <string>
+
+#include "base/optional.h"
+#include "base/strings/string_util.h"
+#include "base/time/time.h"
+#include "chrome/browser/page_load_metrics/page_load_metrics_util.h"
+#include "chrome/common/page_load_metrics/page_load_timing.h"
+#include "components/google/core/browser/google_util.h"
+#include "content/public/browser/navigation_handle.h"
+#include "url/gurl.h"
+
+namespace {
+
+const char kHistogramAMPDOMContentLoadedEventFired[] =
+    "PageLoad.Clients.AMPCache.DocumentTiming."
+    "NavigationToDOMContentLoadedEventFired";
+const char kHistogramAMPFirstLayout[] =
+    "PageLoad.Clients.AMPCache.DocumentTiming.NavigationToFirstLayout";
+const char kHistogramAMPLoadEventFired[] =
+    "PageLoad.Clients.AMPCache.DocumentTiming.NavigationToLoadEventFired";
+const char kHistogramAMPFirstContentfulPaint[] =
+    "PageLoad.Clients.AMPCache.PaintTiming.NavigationToFirstContentfulPaint";
+const char kHistogramAMPParseStart[] =
+    "PageLoad.Clients.AMPCache.ParseTiming.NavigationToParseStart";
+
+// Host pattern for AMP Cache URLs.
+// See https://developers.google.com/amp/cache/overview#amp-cache-url-format
+// for a definition of the format of AMP Cache URLs.
+const char kAmpCacheHost[] = "cdn.ampproject.org";
+
+// Pattern for the path of Google AMP Viewer URLs.
+const char kGoogleAmpViewerPathPattern[] = "/amp/";
+
+bool IsAMPCacheURL(const GURL& url) {
+  return url.host() == kAmpCacheHost ||
+         (google_util::IsGoogleDomainUrl(
+              url, google_util::DISALLOW_SUBDOMAIN,
+              google_util::DISALLOW_NON_STANDARD_PORTS) &&
+          base::StartsWith(url.path(), kGoogleAmpViewerPathPattern,
+                           base::CompareCase::SENSITIVE));
+}
+
+}  // namespace
+
+AMPPageLoadMetricsObserver::AMPPageLoadMetricsObserver() {}
+
+AMPPageLoadMetricsObserver::~AMPPageLoadMetricsObserver() {}
+
+page_load_metrics::PageLoadMetricsObserver::ObservePolicy
+AMPPageLoadMetricsObserver::OnCommit(
+    content::NavigationHandle* navigation_handle) {
+  return IsAMPCacheURL(navigation_handle->GetURL()) ? CONTINUE_OBSERVING
+                                                    : STOP_OBSERVING;
+}
+
+void AMPPageLoadMetricsObserver::OnDomContentLoadedEventStart(
+    const page_load_metrics::PageLoadTiming& timing,
+    const page_load_metrics::PageLoadExtraInfo& info) {
+  if (!WasStartedInForegroundOptionalEventInForeground(
+          timing.dom_content_loaded_event_start, info)) {
+    return;
+  }
+  PAGE_LOAD_HISTOGRAM(kHistogramAMPDOMContentLoadedEventFired,
+                      timing.dom_content_loaded_event_start.value());
+}
+
+void AMPPageLoadMetricsObserver::OnLoadEventStart(
+    const page_load_metrics::PageLoadTiming& timing,
+    const page_load_metrics::PageLoadExtraInfo& info) {
+  if (!WasStartedInForegroundOptionalEventInForeground(
+          timing.dom_content_loaded_event_start, info)) {
+    return;
+  }
+  PAGE_LOAD_HISTOGRAM(kHistogramAMPLoadEventFired,
+                      timing.load_event_start.value());
+}
+
+void AMPPageLoadMetricsObserver::OnFirstLayout(
+    const page_load_metrics::PageLoadTiming& timing,
+    const page_load_metrics::PageLoadExtraInfo& info) {
+  if (!WasStartedInForegroundOptionalEventInForeground(
+          timing.dom_content_loaded_event_start, info)) {
+    return;
+  }
+  PAGE_LOAD_HISTOGRAM(kHistogramAMPFirstLayout, timing.first_layout.value());
+}
+
+void AMPPageLoadMetricsObserver::OnFirstContentfulPaint(
+    const page_load_metrics::PageLoadTiming& timing,
+    const page_load_metrics::PageLoadExtraInfo& info) {
+  if (!WasStartedInForegroundOptionalEventInForeground(
+          timing.dom_content_loaded_event_start, info)) {
+    return;
+  }
+  PAGE_LOAD_HISTOGRAM(kHistogramAMPFirstContentfulPaint,
+                      timing.first_contentful_paint.value());
+}
+
+void AMPPageLoadMetricsObserver::OnParseStart(
+    const page_load_metrics::PageLoadTiming& timing,
+    const page_load_metrics::PageLoadExtraInfo& info) {
+  if (!WasStartedInForegroundOptionalEventInForeground(
+          timing.dom_content_loaded_event_start, info)) {
+    return;
+  }
+  PAGE_LOAD_HISTOGRAM(kHistogramAMPParseStart, timing.parse_start.value());
+}