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

content/plugin/plugin_interpose_util_mac.mm

 // Copyright (c) 2011 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/plugin/plugin_interpose_util_mac.h"
 
 #import <AppKit/AppKit.h>
 #import <objc/runtime.h>
 
 #include "content/common/plugin_messages.h"
@@ skipping 68 matching lines @@
   }
 }
 
 }  // namespace mac_plugin_interposing
 
 #pragma mark -
 
 struct WindowInfo {
   uint32 window_id;
   CGRect bounds;
-  WindowInfo(NSWindow* window) {
+  explicit WindowInfo(NSWindow* window) {
     NSInteger window_num = [window windowNumber];
     window_id = window_num > 0 ? window_num : 0;
     bounds = NSRectToCGRect([window frame]);
   }
 };
 
 static void OnPluginWindowClosed(const WindowInfo& window_info) {
   if (window_info.window_id == 0)
     return;
   mac_plugin_interposing::NotifyBrowserOfPluginHideWindow(window_info.window_id,
@@ skipping 168 matching lines @@
   Class nscursor_class = [NSCursor class];
   ExchangeMethods(nscursor_class, NO, @selector(set),
                   @selector(chromePlugin_set));
   ExchangeMethods(nscursor_class, YES, @selector(hide),
                   @selector(chromePlugin_hide));
   ExchangeMethods(nscursor_class, YES, @selector(unhide),
                   @selector(chromePlugin_unhide));
 }
 
 }  // namespace mac_plugin_interposing