[PPAPI] Fix a bunch of spelling mistakes

ppapi/cpp/url_loader.h

Index: ppapi/cpp/url_loader.h
diff --git a/ppapi/cpp/url_loader.h b/ppapi/cpp/url_loader.h
index 3ed5fe6e9255109ce323ef70b8a9bcce46f83846..00c086e14d5fdb37d58d5ec00910d496dd1de0ef 100644
--- a/ppapi/cpp/url_loader.h
+++ b/ppapi/cpp/url_loader.h
@@ -54,7 +54,7 @@ class URLLoader : public Resource {
   /// URLRequestInfo.
   /// @param[in] cc A <code>CompletionCallback</code> to run on asynchronous
   /// completion of Open(). This callback will run when response
-  /// headers for the url are received or error occured. This callback
+  /// headers for the url are received or error occurred. This callback
   /// will only run if Open() returns <code>PP_OK_COMPLETIONPENDING</code>.
   ///
   /// @return An int32_t containing an error code from
@@ -67,7 +67,7 @@ class URLLoader : public Resource {
   ///
   /// @param[in] cc A <code>CompletionCallback</code> to run on asynchronous
   /// completion of FollowRedirect(). This callback will run when response
-  /// headers for the redirect url are received or error occured. This callback
+  /// headers for the redirect url are received or error occurred. This callback
   /// will only run if FollowRedirect() returns
   /// <code>PP_OK_COMPLETIONPENDING</code>.
   ///