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

Source/core/css/CSSHostRule.idl

Index: Source/core/css/CSSHostRule.idl
diff --git a/Source/core/css/CSSHostRule.idl b/Source/core/css/CSSHostRule.idl
index 1f7808826d4ecddd794cb16d891e199b8cb37d37..237a051eedb0142725ace8259e0398ac476b0138 100644
--- a/Source/core/css/CSSHostRule.idl
+++ b/Source/core/css/CSSHostRule.idl
@@ -21,8 +21,8 @@
 // Introduced in Shadow DOM spec:
 interface CSSHostRule : CSSRule {
     readonly attribute CSSRuleList cssRules;
-    
-    [RaisesException] unsigned long      insertRule([Default=Undefined] optional DOMString rule, 
+
+    [RaisesException] unsigned long      insertRule([Default=Undefined] optional DOMString rule,
                                   [Default=Undefined] optional unsigned long index);
     [RaisesException] void               deleteRule([Default=Undefined] optional unsigned long index);
 };