Fix trailing whitespace in .cpp, .h, and .idl files

Source/core/loader/Prerenderer.cpp

Index: Source/core/loader/Prerenderer.cpp
diff --git a/Source/core/loader/Prerenderer.cpp b/Source/core/loader/Prerenderer.cpp
index 5afa94f9d7f040b8b2515c7263f6cb3f43be199c..1360d78c415ba4105be085a31303c8a64ed5f5d9 100644
--- a/Source/core/loader/Prerenderer.cpp
+++ b/Source/core/loader/Prerenderer.cpp
@@ -71,7 +71,7 @@ PassRefPtr<PrerenderHandle> Prerenderer::render(PrerenderClient* prerenderClient
     // Prerenders are unlike requests in most ways (for instance, they pass down fragments, and they don't return data),
     // but they do have referrers.
     const ReferrerPolicy referrerPolicy = document()->referrerPolicy();
-    
+
     if (!document()->frame())
         return 0;