Rename DesktopEngagement* to DesktopSessionDuration*.

chrome/browser/metrics/desktop_engagement/desktop_engagement_observer.h

Index: chrome/browser/metrics/desktop_engagement/desktop_engagement_observer.h
diff --git a/chrome/browser/metrics/desktop_engagement/desktop_engagement_observer.h b/chrome/browser/metrics/desktop_engagement/desktop_engagement_observer.h
deleted file mode 100644
index 89bd188cd3dd3bfaa60cb03e1677fb9f04c9cc3c..0000000000000000000000000000000000000000
--- a/chrome/browser/metrics/desktop_engagement/desktop_engagement_observer.h
+++ /dev/null
@@ -1,54 +0,0 @@
-// 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_METRICS_DESKTOP_ENGAGEMENT_DESKTOP_ENGAGEMENT_OBSERVER_H_
-#define CHROME_BROWSER_METRICS_DESKTOP_ENGAGEMENT_DESKTOP_ENGAGEMENT_OBSERVER_H_
-
-#include "base/macros.h"
-#include "content/public/browser/render_widget_host.h"
-#include "content/public/browser/web_contents.h"
-#include "content/public/browser/web_contents_observer.h"
-#include "content/public/browser/web_contents_user_data.h"
-#include "third_party/WebKit/public/web/WebInputEvent.h"
-
-namespace metrics {
-
-class DesktopEngagementService;
-
-// Tracks user input events from web contents and notifies
-// |DesktopEngagementService|.
-class DesktopEngagementObserver
-    : public content::WebContentsObserver,
-      public content::WebContentsUserData<DesktopEngagementObserver>,
-      public content::RenderWidgetHost::InputEventObserver {
- public:
-  DesktopEngagementObserver(content::WebContents* web_contents,
-                            DesktopEngagementService* service);
-  ~DesktopEngagementObserver() override;
-
-  static DesktopEngagementObserver* CreateForWebContents(
-      content::WebContents* web_contents);
-
- private:
-  friend class content::WebContentsUserData<DesktopEngagementObserver>;
-
-  // Register / Unregister input event callback to given RenderViewHost
-  void RegisterInputEventObserver(content::RenderViewHost* host);
-  void UnregisterInputEventObserver(content::RenderViewHost* host);
-
-  // content::RenderWidgetHost::InputEventObserver:
-  void OnInputEvent(const blink::WebInputEvent& event) override;
-
-  // content::WebContentsObserver:
-  void RenderViewHostChanged(content::RenderViewHost* old_host,
-                             content::RenderViewHost* new_host) override;
-
-  DesktopEngagementService* service_;
-
-  DISALLOW_COPY_AND_ASSIGN(DesktopEngagementObserver);
-};
-
-}  // namespace metrics
-
-#endif  // CHROME_BROWSER_METRICS_DESKTOP_ENGAGEMENT_DESKTOP_ENGAGEMENT_OBSERVER_H_