<AWT Dev> RFR: 8196300: java/awt/TextArea/TextAreaScrolling/TextAreaScrolling.java times out

[Prasanta Sadhukhan]

This test was timing out on windows during nightly testing possibly due to samevm mode issue when it was problemlisted.
Modified test to increase the timing delay after frame is made visible, added waitForIdle() at suitable places and delays to make sure the execution steps are visible during execution.
Modified test pass in several iterations in all platforms.

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Commit messages:
 - 8196300: java/awt/TextArea/TextAreaScrolling/TextAreaScrolling.java times out

Changes: https://git.openjdk.java.net/jdk/pull/3686/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3686&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8196300
  Stats: 16 lines in 2 files changed: 5 ins; 1 del; 10 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3686.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3686/head:pull/3686

PR: https://git.openjdk.java.net/jdk/pull/3686