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

content/renderer/pepper/pepper_plugin_delegate_impl.cc

 // 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.
 
 #include "content/renderer/pepper/pepper_plugin_delegate_impl.h"
 
 #include <cmath>
 #include <cstddef>
 #include <map>
 #include <queue>
@@ skipping 212 matching lines @@
   }
   virtual void DidFail(quota::QuotaStatusCode error) OVERRIDE {
     callback_.Run(0);
   }
  private:
   PluginCallback callback_;
 };
 
 class PluginInstanceLockTarget : public MouseLockDispatcher::LockTarget {
  public:
-  PluginInstanceLockTarget(webkit::ppapi::PluginInstance* plugin)
+  explicit PluginInstanceLockTarget(webkit::ppapi::PluginInstance* plugin)
       : plugin_(plugin) {}
 
   virtual void OnLockMouseACK(bool succeeded) OVERRIDE {
     plugin_->OnLockMouseACK(succeeded);
   }
 
   virtual void OnMouseLockLost() OVERRIDE {
     plugin_->OnMouseLockLost();
   }
 
@@ skipping 1485 matching lines @@
     RenderWidgetFullscreenPepper* container =
         static_cast<RenderWidgetFullscreenPepper*>(
             instance->fullscreen_container());
     return container->mouse_lock_dispatcher();
   } else {
     return render_view_->mouse_lock_dispatcher();
   }
 }
 
 }  // namespace content