RFR: 8202990: javafx webview css filter property with display scaling

[Bhawesh Choudhary]

ImageJava.cpp ignores CompositeOperator parameter in drawImage function due to which shadow was getting drawn on top of
actual image. apply given composite operator to graphics context before drawing image to fix this issue. another issue
is into WCGraphicsPrismContext.java. while blending two layers, applying state to the destination layer was missed due
to which image was not getting drawn with right scale in hidpi mode. apply state to fix the issue.

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Commit messages:
 - Formatting
 - Formatting
 - added Unit Test
 - 8202990: javafx webview css filter property with display scaling

Changes: https://git.openjdk.java.net/jfx/pull/279/files
 Webrev: https://webrevs.openjdk.java.net/jfx/279/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8202990
  Stats: 46 lines in 4 files changed: 45 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jfx/pull/279.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/279/head:pull/279

PR: https://git.openjdk.java.net/jfx/pull/279