RFR: JDK-8255439: System Tray icons get corrupted when windows scaling changes [v8]

[Harshitha Onkar]

> In Windows, when desktop scaling is changed the tray icons was distorted/blurred a bit each time scaling changes.
> 
> With the proposed fix, the tray icon scales according to on-the-fly DPI scale settings. A test case has been added which adds a MRI icon to system tray, to observe the icon scaling when DPI is changed. Since the scale cannot be programmatically changed (for dynamic on-the-fly scale changes), I have used a manual test case to test this scenario.
> 
> When DPI changes usually two messages are sent by windows -
> 
> - [WM_DPICHANGED](https://docs.microsoft.com/en-us/windows/win32/hidpi/wm-dpichanged)
> - [WMPOSCHANGING](https://docs.microsoft.com/en-us/windows/win32/winmsg/wm-windowposchanging)
> 
> I'm triggering an update on tray icons on receiving WMPOSCHANGING msg through the Tray icon's Window Procedure. Triggering an update on WM_DPICHANGED was still causing the icons to be distorted, hence WMPOSCHANGING is being used as the message to trigger the update.

Harshitha Onkar has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 11 additional commits since the last revision:

 - Merge branch 'master' into WinTrayIcon
 - reverted SystemTray changes
 - new changes - trayicon update triggered in WmTaskbarCreated
 - trayicon update triggered on taskbar reload
 - test case exit issue fix
 - formatting changes
 - resized instruction window and formatted line lengths
 - removed whitespaces error due to CRLF
 - removed whitespace error
 - added manual to test case
 - ... and 1 more: https://git.openjdk.java.net/jdk/compare/9ac0120d...60391f28

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8441/files
  - new: https://git.openjdk.java.net/jdk/pull/8441/files/8f144b3b..60391f28

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8441&range=07
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8441&range=06-07

  Stats: 216539 lines in 2758 files changed: 164744 ins; 37288 del; 14507 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8441.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8441/head:pull/8441

PR: https://git.openjdk.java.net/jdk/pull/8441