Deleting across multiple paragraphs can change the style of surrounding text

Deleting across multiple paragraphs can change the style of surrounding text
https://bugs.webkit.org/show_bug.cgi?id=97266

Reviewed by Levi Weintraub.

Source/WebCore:

Preserve editing styles from CSS rules in wrappingStyleForSerialization as well as inline styles
even when we're not annotating. We don't want to preserve all styles because it's against
the user expectation to keep borders, etc... when merging paragraphs. We also don't want to copy
styles from a mail blockquote because that's not a style the user has applied. See the comment
in EditingStyle::wrappingStyleForSerialization.

Test: editing/deleting/merge-paragraph-with-style-from-rule.html

* editing/EditingStyle.cpp:
(WebCore::EditingStyle::mergeInlineAndImplicitStyleOfElement):
(WebCore::EditingStyle::wrappingStyleForSerialization):

LayoutTests:

Added a regression test and rebaselined tests.

* editing/deleting/delete-before-block-image-2-expected.txt:
* editing/deleting/merge-paragraph-from-p-with-style-expected.txt:
* editing/deleting/merge-paragraph-from-p-with-style.html: We changed the behavior. The editing style of p
is now preserved when merging paragraphs.
* editing/deleting/merge-paragraph-with-style-from-rule-expected.txt: Added.
* editing/deleting/merge-paragraph-with-style-from-rule.html: Added.
* platform/mac/editing/deleting/delete-block-merge-contents-001-expected.txt:
* platform/mac/editing/pasteboard/merge-end-blockquote-expected.txt:

Change-Id: I1965220755b35616dbb6c48608047b241a3b3d5f
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@130532 268f45cc-cd09-0410-ab3c-d52691b4dbfc