FrameBorder and DialogBorder had border scaling issues similar to JInternalFrame. This fix addresses it by creating `AbstractMetalBorder` class that contains the common steps required for painting border for `FrameBorder`, `DialogBorder` and `InternalFrameBorder`.
All 3 cases - JFrame, JDialog and JInternalFrame are combined into a single test case - `ScaledMetalBorderTest` and hence the older `InternalFrameBorderTest` which is no longer required, is deleted. ------------- Commit messages: - added updateColor(), isActive() to MetalBorder - test summary changes - deleted InternalFrameBorderTest - moved corner var to AbstractMetalBorder - sealed abstract class, record changes - initial commit, consolidated test case Changes: https://git.openjdk.org/jdk/pull/12391/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12391&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8294484 Stats: 786 lines in 3 files changed: 389 ins; 327 del; 70 mod Patch: https://git.openjdk.org/jdk/pull/12391.diff Fetch: git fetch https://git.openjdk.org/jdk pull/12391/head:pull/12391 PR: https://git.openjdk.org/jdk/pull/12391
