Add common page filtering logic for page load metrics.

chrome/browser/page_load_metrics/browser_page_track_decider.h

+// 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.
+
+#ifndef CHROME_BROWSER_PAGE_LOAD_METRICS_BROWSER_PAGE_TRACK_DECIDER_H_
+#define CHROME_BROWSER_PAGE_LOAD_METRICS_BROWSER_PAGE_TRACK_DECIDER_H_
+
+#include "base/macros.h"
+#include "chrome/common/page_load_metrics/page_track_decider.h"
+
+namespace content {
+class NavigationHandle;
+class WebContents;
+}  // namespace content
+
+namespace page_load_metrics {
+
+class PageLoadMetricsEmbedderInterface;
+
+class BrowserPageTrackDecider : public PageTrackDecider {
+ public:
+  // embedder_interface, web_contents, and navigation_handle are not owned by
+  // BrowserPageTrackDecider, and must outlive the
+  // BrowserPageTrackDecider.
+  BrowserPageTrackDecider(PageLoadMetricsEmbedderInterface* embedder_interface,
+                          content::WebContents* web_contents,
+                          content::NavigationHandle* navigation_handle);
+  ~BrowserPageTrackDecider() override;
+

[Charlie Harrison, 2016/09/14 13:20:05]

// PageTrackDecider:

[Bryan McQuade, 2016/09/14 15:10:58]

I think this is a bit redundant in this case, as PageTrackDecider is the only
interface we inherit, so overridden methods must be from the base class, and we
don't add any new methods to the API.

If this is part of Chromium style guide I'm happy to add it but otherwise in
this case I don't think it adds value.

[Charlie Harrison, 2016/09/14 16:27:32]

Nope, just a convention we've been using. Happy to defer to your personal style
in this case.

+  bool HasCommitted() override;
+  bool IsHTTPOrHTTPSUrl() override;
+  bool IsNewTabPageUrl() override;
+  bool IsChromeErrorPage() override;
+  bool IsHTTPErrorPage() override;
+  bool IsHTMLOrXHTMLPage() override;
+
+ private:
+  PageLoadMetricsEmbedderInterface* const embedder_interface_;
+  content::WebContents* const web_contents_;
+  content::NavigationHandle* const navigation_handle_;
+
+  DISALLOW_COPY_AND_ASSIGN(BrowserPageTrackDecider);
+};
+
+}  // namespace page_load_metrics
+
+#endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_BROWSER_PAGE_TRACK_DECIDER_H_