Move RoundedRect from core/platform/graphics to platform/geometry

Move the RoundedRect class and tests from core/platform/graphics into
the the geometry directory in the new platform module.

Originally landed as r158824 but rolled out due to a win debug build
failure.

BUG=297477
R=eseidel@chromium.org, leviw@chromium.org

Review URL: https://codereview.chromium.org/26026004

git-svn-id: svn://svn.chromium.org/blink/trunk@158959 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[CSS Shapes] Revise the CSS property parsing tests

Flattened the shapes CSS property parsing tests by inserting the code from the fast/shapes/parsing/script-tests subdirectory into the test HTML source files. The subdirectory is now empty and the tests are easier to read.

BUG=303859

Review URL: https://codereview.chromium.org/26029002

git-svn-id: svn://svn.chromium.org/blink/trunk@158960 bbb929c8-8fbe-4397-9dbb-9b2b20218538