Add common page filtering logic for page load metrics.

chrome/common/page_load_metrics/page_track_decider.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/common/page_load_metrics/page_track_decider.h"
+
+namespace page_load_metrics {
+
+PageTrackDecider::PageTrackDecider() {}
+PageTrackDecider::~PageTrackDecider() {}
+
+bool PageTrackDecider::ShouldTrack() {
+  // Ignore non-HTTP schemes (e.g. chrome://).
+  if (!IsHttpOrHttpsUrl())
+    return false;
+
+  // Ignore NTP loads.
+  if (IsNewTabPageUrl())
+    return false;
+
+  if (HasCommitted()) {
+    // Ignore Chrome error pages (e.g. No Internet connection).
+    if (IsChromeErrorPage())
+      return false;
+
+    // Ignore non-HTML documents (e.g. SVG, images).
+    if (!IsHtmlOrXhtmlPage())
+      return false;
+
+    // Ignore network error pages (e.g. 4xx, 5xx).
+    int http_status_code = GetHttpStatusCode();
+    if (http_status_code > 0 &&
+        (http_status_code < 200 || http_status_code >= 400))
+      return false;
+  }
+
+  return true;
+}
+
+}  // namespace page_load_metrics