Add tests for shouldIgnoreLine() in filter-build-webkit
Part 2 of 3: <http://webkit.org/b/116247>

Reviewed by Benjamin Poulain.

* Scripts/filter-build-webkit:
(shouldIgnoreLine): Add.  Extract code from global scope into
subroutine to make it testable.
* Scripts/webkitperl/filter-build-webkit_unittest/shouldIgnoreLine_unittests.pl: Add.
Tests shouldIgnoreLine() using output from a real build
transcript.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@150285 268f45cc-cd09-0410-ab3c-d52691b4dbfc
filter-build-webkit: Don't filter out the location of the missing symbol when linking fails
Part 3 of 3: <http://webkit.org/b/116247>

Reviewed by Benjamin Poulain.

* Scripts/filter-build-webkit: Change while() loop to for() loop
to track $previousLine, then pass $previousLine into
shouldIgnoreLine().
(shouldIgnoreLine): Add $previousLine argument. Do not skip a
line that begins with four spaces if the previous line is a
linker error message.
* Scripts/webkitperl/filter-build-webkit_unittest/shouldIgnoreLine_unittests.pl:
- Add "Ignored: " to test descriptions to document expected
  behavior.
- Add comment blocks for various groups of tests.
- Expand "Build settings" tests since we're changing the code in
  shouldIgnoreLine() that ignores those lines.
- Add tests for undefined symbols error message.
(description): Add.  Extract from global code.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@150286 268f45cc-cd09-0410-ab3c-d52691b4dbfc