[jdk8u-dev] RFR: 8346887: DrawFocusRect() may cause an assertion failure

[Satyen Subramaniam]

Backporting JDK-8346887: DrawFocusRect() may cause an assertion failure. Minor change that adds an additional check before running an assertion for windows. Ran GHA Sanity Checks and local Tier 1 and Tier 2 tests. Patch is nearly clean, adjusting header comments.

-------------

Commit messages:
 - Backport 8eddf67

Changes: https://git.openjdk.org/jdk8u-dev/pull/614/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=614&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8346887
  Stats: 11 lines in 3 files changed: 4 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/614.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/614/head:pull/614

PR: https://git.openjdk.org/jdk8u-dev/pull/614