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

Source/core/loader/PingLoader.h

Index: Source/core/loader/PingLoader.h
diff --git a/Source/core/loader/PingLoader.h b/Source/core/loader/PingLoader.h
index 418e420d35acf5de275227c26f1d3c973fba6139..a25a5c68eb0d75380b2df2989d053c9b6011de62 100644
--- a/Source/core/loader/PingLoader.h
+++ b/Source/core/loader/PingLoader.h
@@ -51,7 +51,7 @@ class ResourceResponse;
 // This class triggers asynchronous loads independent of Frame staying alive (i.e., auditing pingbacks).
 // Since nothing depends on resources loaded through this class, we just want
 // to allow the load to live long enough to ensure the message was actually sent.
-// Therefore, as soon as a callback is received from the ResourceHandle, this class 
+// Therefore, as soon as a callback is received from the ResourceHandle, this class
 // will cancel the load and delete itself.
 class PingLoader : private WebKit::WebURLLoaderClient {
     WTF_MAKE_NONCOPYABLE(PingLoader); WTF_MAKE_FAST_ALLOCATED;