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

remoting/client/frame_consumer_proxy.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.
 
 // FrameConsumerProxy is used to allow a FrameConsumer on the UI thread to be
 // invoked by a Decoder on the decoder thread.  The Detach() method is used by
 // the proxy's owner before tearing down the FrameConsumer, to prevent any
 // further invokations reaching it.
 
 #ifndef REMOTING_CLIENT_FRAME_CONSUMER_PROXY_H_
 #define REMOTING_CLIENT_FRAME_CONSUMER_PROXY_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "remoting/client/frame_consumer.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace remoting {
 
 class FrameConsumerProxy
     : public base::RefCountedThreadSafe<FrameConsumerProxy>,
       public FrameConsumer {
  public:
   // Constructs a proxy for |frame_consumer| which will trampoline invocations
   // to |frame_consumer_message_loop|.
-  FrameConsumerProxy(scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+  explicit FrameConsumerProxy(
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
 
   // FrameConsumer implementation.
   virtual void ApplyBuffer(const SkISize& view_size,
                            const SkIRect& clip_area,
                            pp::ImageData* buffer,
                            const SkRegion& region) OVERRIDE;
   virtual void ReturnBuffer(pp::ImageData* buffer) OVERRIDE;
   virtual void SetSourceSize(const SkISize& source_size,
                              const SkIPoint& dpi) OVERRIDE;
 
   // Attaches to |frame_consumer_|.
   // This must only be called from |frame_consumer_message_loop_|.
   void Attach(const base::WeakPtr<FrameConsumer>& frame_consumer);
 
  private:
   friend class base::RefCountedThreadSafe<FrameConsumerProxy>;
   virtual ~FrameConsumerProxy();
 
   base::WeakPtr<FrameConsumer> frame_consumer_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameConsumerProxy);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_CLIENT_FRAME_CONSUMER_PROXY_H_