RFR: 8233747: JVM crash in com.sun.webkit.dom.DocumentImpl.createAttribute

[Arun Joseph]

Issue: Native part of WebView throws a DOMException and then, continues executing the rest of the function assuming that value is present. This causes the JVM to crash when retrieving the value.

Fix: Return from the function if exception was raised (code is similar to exception handling in [WebKitLegacy/java/DOM/JavaTreeWalker.cpp](https://github.com/openjdk/jfx/blob/master/modules/javafx.web/src/main/native/Source/WebKitLegacy/java/DOM/JavaTreeWalker.cpp))

This fix also needs to be applied to all function calls in [WebKitLegacy/java/DOM](https://github.com/openjdk/jfx/tree/master/modules/javafx.web/src/main/native/Source/WebKitLegacy/java/DOM) functions which raises DOMError similar to createAttributeImpl().

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Commits:
 - acc52780: 8233747: JVM crash in com.sun.webkit.dom.DocumentImpl.createAttribute

Changes: https://git.openjdk.java.net/jfx/pull/47/files
 Webrev: https://webrevs.openjdk.java.net/jfx/47/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8233747
  Stats: 7 lines in 1 file changed: 6 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jfx/pull/47.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/47/head:pull/47

PR: https://git.openjdk.java.net/jfx/pull/47