Add missing (and remove superfluous) 'explicit' from constructors.

chrome/browser/policy/configuration_policy_handler.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_POLICY_CONFIGURATION_POLICY_HANDLER_H_
 #define CHROME_BROWSER_POLICY_CONFIGURATION_POLICY_HANDLER_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 234 matching lines @@
   virtual void ApplyPolicySettings(const PolicyMap& policies,
                                    PrefValueMap* prefs) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DownloadDirPolicyHandler);
 };
 
 // ConfigurationPolicyHandler for the DiskCacheDir policy.
 class DiskCacheDirPolicyHandler : public TypeCheckingPolicyHandler {
  public:
-  explicit DiskCacheDirPolicyHandler();
+  DiskCacheDirPolicyHandler();
   virtual ~DiskCacheDirPolicyHandler();
 
   // ConfigurationPolicyHandler methods:
   virtual void ApplyPolicySettings(const PolicyMap& policies,
                                    PrefValueMap* prefs) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DiskCacheDirPolicyHandler);
 };
 
@@ skipping 192 matching lines @@
  private:
   void ApplyPolicySettingsFromHomePage(const PolicyMap& policies,
                                        PrefValueMap* prefs);
 
   DISALLOW_COPY_AND_ASSIGN(RestoreOnStartupPolicyHandler);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_CONFIGURATION_POLICY_HANDLER_H_