RFR: 8275715: D3D pipeline processes multiple PaintEvent at initial drawing

[Masanori Yano]

Could you please review the 8275715 bug fixes?

I think D3DScreenUpdateManager posts unnecessary PaintEvent during processing PaintEvent. When the validate method is called from createGraphics, repaintPeerTarget should not be called.

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Commit messages:
 - 8275715: D3D pipeline processes multiple PaintEvent at initial drawing

Changes: https://git.openjdk.java.net/jdk/pull/6064/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6064&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8275715
  Stats: 86 lines in 2 files changed: 82 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6064.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6064/head:pull/6064

PR: https://git.openjdk.java.net/jdk/pull/6064