ObserverList::HasObserver now takes a const pointer.

chrome/browser/extensions/api/dial/dial_service.h

 // Copyright (c) 2012 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_EXTENSIONS_API_DIAL_DIAL_SERVICE_H_
 #define CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_SERVICE_H_
 
 #include <string>
 
 #include "base/gtest_prod_util.h"
@@ skipping 71 matching lines @@
 
   virtual ~DialService() {}
 
   // Starts a new round of discovery.  Returns |true| if discovery was started
   // successfully or there is already one active. Returns |false| on error.
   virtual bool Discover() = 0;
 
   // Called by listeners to this service to add/remove themselves as observers.
   virtual void AddObserver(Observer* observer) = 0;
   virtual void RemoveObserver(Observer* observer) = 0;
-  virtual bool HasObserver(Observer* observer) = 0;
+  virtual bool HasObserver(const Observer* observer) const = 0;
 };
 
 // Implements DialService.
 //
 // NOTE(mfoltz): It would make this class cleaner to refactor most of the state
 // associated with a single discovery cycle into its own |DiscoveryOperation|
 // object.  This would also simplify lifetime of the object w.r.t. DialRegistry;
 // the Registry would not need to create/destroy the Service on demand.
 class DialServiceImpl : public DialService,
                         public base::SupportsWeakPtr<DialServiceImpl> {
  public:
   explicit DialServiceImpl(net::NetLog* net_log);
   ~DialServiceImpl() override;
 
   // DialService implementation
   bool Discover() override;
   void AddObserver(Observer* observer) override;
   void RemoveObserver(Observer* observer) override;
-  bool HasObserver(Observer* observer) override;
+  bool HasObserver(const Observer* observer) const override;
 
  private:
   // Represents a socket binding to a single network interface.
   class DialSocket {
    public:
     // TODO(imcheng): Consider writing a DialSocket::Delegate interface that
     // declares methods for these callbacks, and taking a ptr to the delegate
     // here.
     DialSocket(
         const base::Closure& discovery_request_cb,
@@ skipping 172 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(DialServiceTest, TestOnDeviceDiscovered);
   FRIEND_TEST_ALL_PREFIXES(DialServiceTest, TestOnDiscoveryFinished);
   FRIEND_TEST_ALL_PREFIXES(DialServiceTest, TestOnDiscoveryRequest);
   FRIEND_TEST_ALL_PREFIXES(DialServiceTest, TestResponseParsing);
   DISALLOW_COPY_AND_ASSIGN(DialServiceImpl);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_DIAL_DIAL_SERVICE_H_