Fix trailing whitespace in .cpp, .h, and .idl files (ex. Source/core)

Source/wtf/dtoa.cpp

Index: Source/wtf/dtoa.cpp
diff --git a/Source/wtf/dtoa.cpp b/Source/wtf/dtoa.cpp
index 2949961888f20d0ff56f69f52dd82f30ffb8fd0d..1d601bde5081fa267ced6aa0dd708715ce62b6b3 100644
--- a/Source/wtf/dtoa.cpp
+++ b/Source/wtf/dtoa.cpp
@@ -1292,7 +1292,7 @@ const char* numberToFixedWidthString(double d, unsigned decimalPlaces, NumberToS
     // the number of digits after the decimal point depends on the requested precision.
     // "precision": The precision value specifies the number of digits after the decimal point.
     // If a decimal point appears, at least one digit appears before it.
-    // The value is rounded to the appropriate number of digits.    
+    // The value is rounded to the appropriate number of digits.
     double_conversion::StringBuilder builder(buffer, NumberToStringBufferLength);
     const double_conversion::DoubleToStringConverter& converter = double_conversion::DoubleToStringConverter::EcmaScriptConverter();
     converter.ToFixed(d, decimalPlaces, &builder);