Bug 1519636 - clang-format-8: Reformat recent changes to the Google coding style r=Ehsan

clang-format-8 upstream had some improvements wrt macros
See: https://reviews.llvm.org/D33440
This is why the diff is bigger than usual

# ignore-this-changeset

Differential Revision: https://phabricator.services.mozilla.com/D26098

dom/xhr/XMLHttpRequestMainThread.cpp

@@ -1491,8 +1491,8 @@ nsresult XMLHttpRequestMainThread::StreamReaderFunc(
     xmlHttpRequest->MaybeCreateBlobStorage();
     rv = xmlHttpRequest->mBlobStorage->Append(fromRawSegment, count);
   } else if (xmlHttpRequest->mResponseType ==
-                  XMLHttpRequestResponseType::Arraybuffer &&
-              !xmlHttpRequest->mIsMappedArrayBuffer) {
+                 XMLHttpRequestResponseType::Arraybuffer &&
+             !xmlHttpRequest->mIsMappedArrayBuffer) {
     // get the initial capacity to something reasonable to avoid a bunch of
     // reallocs right at the start
     if (xmlHttpRequest->mArrayBufferBuilder.capacity() == 0)