RFR: 8280182: HotSpot Style Guide has stale link to chromium style guide

[Liam Miller-Cushon]

Update links to the chromium style guide in the HotSpot Style Guide.

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Commit messages:
 - 8280182: HotSpot Style Guide has stale link to chromium style guide

Changes: https://git.openjdk.java.net/jdk/pull/7138/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7138&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8280182
  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7138.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7138/head:pull/7138

PR: https://git.openjdk.java.net/jdk/pull/7138