Return reference from styleEngine() accessor.

The m_styleEngine member of Document is created in the constructor and
only cleared when the OwnPtr goes out of scope as Document is destroyed.

Changed the styleEngine() accessor to return a reference with an ASSERT
checking that it is never null.

Removed null checks in Document::~Document() and styleResolverChanged()
where the styleEngine cannot be null.

Removed the clearStyleResolver method from Document since it was only
used inside the Document implementation.

R=morrita@chromium.org

Review URL: https://codereview.chromium.org/975933002

git-svn-id: svn://svn.chromium.org/blink/trunk@191302 bbb929c8-8fbe-4397-9dbb-9b2b20218538
42 files changed
tree: 7ad9cf4e8a54941ac8ce056cfa9c2718714aefc5
  1. third_party/