Prevent a crash caused by specifying a CSS Shape geometry Length attribute with a calc() expression. 

The basicShapeForValue() function now specifies the CalculatedConversion option when converting CSSPrimitiveValues to Lengths and the valueForBasicShape() function uses CSSPrimitiveValue::createValue(const Length&, const RenderStyle*) to convert from Lengths back to CSSPrimitiveValues.


BUG=300145

Review URL: https://codereview.chromium.org/25241004

git-svn-id: svn://svn.chromium.org/blink/trunk@158565 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move Decimal.cpp/.h and DecimalTest.cpp to Source/platform/

BUG=297477

Review URL: https://codereview.chromium.org/25332002

git-svn-id: svn://svn.chromium.org/blink/trunk@158566 bbb929c8-8fbe-4397-9dbb-9b2b20218538