Copy a few selection related methods to WebFrame from WebView.

The old methods are temporarily left on WebView until Chrome switches.

Also remove WebView::isSelectionEditable since it's not called.

BUG=304341

Review URL: https://codereview.chromium.org/201773005

git-svn-id: svn://svn.chromium.org/blink/trunk@169968 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add UseCounters for NamedNodeMap functions

This is in order to help determine which of these need to be kept in the
DOM spec, since it looks like some of them will be needed:
https://www.w3.org/Bugs/Public/show_bug.cgi?id=21986

BUG=none
NOTRY=true

Review URL: https://codereview.chromium.org/211363003

git-svn-id: svn://svn.chromium.org/blink/trunk@169969 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Don't propagate sandbox flags to an opened window unless triggered entirely by script.

This was regressed in http://src.chromium.org/viewvc/blink?revision=161843&view=revision,
when we started propagating sandbox flags to new windows via FrameLoader::forceSandboxFlags
even if the new window was caused by clicking a link with target="_blank".

BUG=353253
TEST=http/tests/navigation/new-window-sandboxed-iframe.html

Review URL: https://codereview.chromium.org/208853004

git-svn-id: svn://svn.chromium.org/blink/trunk@169970 bbb929c8-8fbe-4397-9dbb-9b2b20218538