Added check for trailing whitespaces and corrected existing violations.

src/macros.py

Index: src/macros.py
diff --git a/src/macros.py b/src/macros.py
index 5ba7ac3afa0307ed04ade9e7a9da043343c205d6..dc1ccdd21e255ecfc11ede542067cdd4f651026d 100644
--- a/src/macros.py
+++ b/src/macros.py
@@ -170,7 +170,7 @@ macro CAPTURE(index) = (3 + (index));
 const CAPTURE0 = 3;
 const CAPTURE1 = 4;
 
-# PropertyDescriptor return value indices - must match 
+# PropertyDescriptor return value indices - must match
 # PropertyDescriptorIndices in runtime.cc.
 const IS_ACCESSOR_INDEX = 0;
 const VALUE_INDEX = 1;