Revert of Change WebContents::last_active_time_ to Time instead of Timeticks.

components/devtools_discovery/basic_target_descriptor.h

 // 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.
 
 #ifndef COMPONENTS_DEVTOOLS_DISCOVERY_BASIC_TARGET_DESCRIPTOR_H_
 #define COMPONENTS_DEVTOOLS_DISCOVERY_BASIC_TARGET_DESCRIPTOR_H_
 
 #include "components/devtools_discovery/devtools_target_descriptor.h"
 
 namespace devtools_discovery {
@@ skipping 10 matching lines @@
   static const char kTypeOther[];
 
   // DevToolsTargetDescriptor implementation.
   std::string GetId() const override;
   std::string GetParentId() const override;
   std::string GetType() const override;
   std::string GetTitle() const override;
   std::string GetDescription() const override;
   GURL GetURL() const override;
   GURL GetFaviconURL() const override;
-  base::Time GetLastActiveTime() const override;
+  base::TimeTicks GetLastActivityTime() const override;
   bool IsAttached() const override;
   scoped_refptr<content::DevToolsAgentHost> GetAgentHost() const override;
   bool Activate() const override;
   bool Close() const override;
 
  protected:
   void set_parent_id(const std::string& parent_id) { parent_id_ = parent_id; }
   void set_type(const std::string& type) { type_ = type; }
   void set_title(const std::string& title) { title_ = title; }
   void set_description(const std::string& desc) { description_ = desc; }
   void set_url(const GURL& url) { url_ = url; }
   void set_favicon_url(const GURL& url) { favicon_url_ = url; }
 
  private:
   scoped_refptr<content::DevToolsAgentHost> agent_host_;
   std::string parent_id_;
   std::string type_;
   std::string title_;
   std::string description_;
   GURL url_;
   GURL favicon_url_;
-  base::Time last_active_time_;
+  base::TimeTicks last_activity_time_;
 };
 
 }  // namespace devtools_discovery
 
 #endif  // COMPONENTS_DEVTOOLS_DISCOVERY_BASIC_TARGET_DESCRIPTOR_H_