Empty RenderInline objects should not be line break objects.

Empty RenderInline objects should not be line break objects.

https://bugs.webkit.org/show_bug.cgi?id=131861
<rdar://problem/15663617>

Reviewed by David Hyatt.

.:
* ManualTests/empty-inline-as-line-break-position.html: Added.
This issue wouldn't reproduce in WebKitTestRunner.

Source/WebCore:
* rendering/line/BreakingContextInlineHeaders.h:
(WebCore::BreakingContext::canBreakAtThisPosition):
Don't break at this position if this is an empty RenderInline.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@167628 268f45cc-cd09-0410-ab3c-d52691b4dbfc