Relanding this as the previous attempt failed due to build errors.

webkit/plugins/webplugininfo.h

 // 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.
 
 #ifndef WEBKIT_PLUGINS_WEBPLUGININFO_H_
 #define WEBKIT_PLUGINS_WEBPLUGININFO_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
-#include "webkit/plugins/webkit_plugins_export.h"
 
 namespace webkit {
 
-struct WEBKIT_PLUGINS_EXPORT WebPluginMimeType {
+struct WebPluginMimeType {
   WebPluginMimeType();
   // A constructor for the common case of a single file extension and an ASCII
   // description.
   WebPluginMimeType(const std::string& m,
                     const std::string& f,
                     const std::string& d);
   ~WebPluginMimeType();
 
   // The name of the mime type (e.g., "application/x-shockwave-flash").
   std::string mime_type;
 
   // A list of all the file extensions for this mime type.
   std::vector<std::string> file_extensions;
 
   // Description of the mime type.
   base::string16 description;
 
   // Extra parameters to include when instantiating the plugin.
   std::vector<base::string16> additional_param_names;
   std::vector<base::string16> additional_param_values;
 };
 
 // Describes an available NPAPI or Pepper plugin.
-struct WEBKIT_PLUGINS_EXPORT WebPluginInfo {
+struct WebPluginInfo {
   enum PluginType {
     PLUGIN_TYPE_NPAPI,
     PLUGIN_TYPE_PEPPER_IN_PROCESS,
     PLUGIN_TYPE_PEPPER_OUT_OF_PROCESS,
     PLUGIN_TYPE_PEPPER_UNSANDBOXED
   };
 
   WebPluginInfo();
   WebPluginInfo(const WebPluginInfo& rhs);
   ~WebPluginInfo();
@@ skipping 21 matching lines @@
   std::vector<WebPluginMimeType> mime_types;
 
   // Plugin type. See the PluginType enum.
   int type;
 
   // When type is PLUGIN_TYPE_PEPPER_* this indicates the permission bits.
   int32 pepper_permissions;
 };
 
 // Checks whether a plugin is a Pepper plugin, enabled or disabled.
-WEBKIT_PLUGINS_EXPORT bool IsPepperPlugin(const WebPluginInfo& plugin);
+bool IsPepperPlugin(const WebPluginInfo& plugin);
 
-WEBKIT_PLUGINS_EXPORT bool IsOutOfProcessPlugin(const WebPluginInfo& plugin);
+bool IsOutOfProcessPlugin(const WebPluginInfo& plugin);
 
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_WEBPLUGININFO_H_