DOM serialization: proper quoting for < and > in HTML attribute values.

< and > should not be quoted in HTML attributes. Internet Explorer and
Firefox do not quote them. Safari (still) does. The DOM serialization
and parsing specification defers to the HTML specification, which says
that < and > should not be quoted.
http://www.w3.org/html/wg/drafts/html/master/syntax.html#attribute's-serialized-name

In XML attributes, < must be quoted. > does not need to be quoted, but
all browsers currently quote both < and > in XML, so we do the same. The
DOM serialization and parsing specification says neither should be
quoted, but there is an outstanding bug, because not quoting < produces
invalid XML.
https://dvcs.w3.org/hg/innerhtml/raw-file/tip/index.html#dfn-concept-serialize-xml-attributes
https://www.w3.org/Bugs/Public/show_bug.cgi?id=24174

This change makes us not quote < and > in HTML attributes, and slightly
expands the test that ensures we quote < and > in XML attributes.

BUG=330949

Review URL: https://codereview.chromium.org/117103003

git-svn-id: svn://svn.chromium.org/blink/trunk@164489 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Copy WebFrameImpl.{cpp,h} to TextFinder.{cpp,h}

This patch copies Source/web/WebFrameImpl.{cpp,h} into Source/web/TextFinder.{cpp,h} for decoupling WebFrameImpl and text finder.

Another patch will complete decoupling.

BUG=

Review URL: https://codereview.chromium.org/119113003

git-svn-id: svn://svn.chromium.org/blink/trunk@164490 bbb929c8-8fbe-4397-9dbb-9b2b20218538