PPAPI: Add an API for setting a custom user agent for URL requests.

ppapi/cpp/url_request_info.h

Index: ppapi/cpp/url_request_info.h
diff --git a/ppapi/cpp/url_request_info.h b/ppapi/cpp/url_request_info.h
index 49e47ae930155ef4dcaf6189429d997e5d3ecd1c..e9ff9ea1c4d7b4febd710b89489d07173abf6a98 100644
--- a/ppapi/cpp/url_request_info.h
+++ b/ppapi/cpp/url_request_info.h
@@ -245,7 +245,6 @@ class URLRequestInfo : public Resource {
     return SetProperty(PP_URLREQUESTPROPERTY_ALLOWCREDENTIALS, enable);
   }
 
-
   /// SetCustomContentTransferEncoding() sets the
   /// <code>PP_URLREQUESTPROPERTY_CUSTOMCONTENTTRANSFERENCODING</code>
   /// (corresponding to a string of type <code>PP_VARTYPE_STRING</code> or
@@ -309,6 +308,25 @@ class URLRequestInfo : public Resource {
     return SetProperty(PP_URLREQUESTPROPERTY_PREFETCHBUFFERLOWERTHRESHOLD,
                        size);
   }
+
+  /// SetCustomUserAgent() sets the
+  /// <code>PP_URLREQUESTPROPERTY_CUSTOMUSERAGENT</code> (corresponding to a
+  /// string of type <code>PP_VARTYPE_STRING</code> or might be set to undefined
+  /// as <code>PP_VARTYPE_UNDEFINED</code>). Set it to a string to set a custom
+  /// user-agent header (if empty, that header will be omitted), or to undefined
+  /// to use the default. Only loaders with universal access (only available on
+  /// trusted implementations) will accept <code>URLRequestInfo</code> objects
+  /// that try to set a custom user agent; if given to a loader without
+  /// universal access, <code>PP_ERROR_BADARGUMENT</code> will result.
+  ///
+  /// @param[in] user_agent A <code>Var</code> containing the property value. To
+  /// use the default user agent, set <code>user_agent</code> to an undefined
+  /// <code>Var</code>.
+  ///
+  /// @return true if successful, false if the parameter is invalid.
+  bool SetCustomUserAgent(const Var& user_agent) {
+    return SetProperty(PP_URLREQUESTPROPERTY_CUSTOMUSERAGENT, user_agent);
+  }
 };
 
 }  // namespace pp