Get rid of explicit editor dependency from text field

This patch removes explicit editor dependency in text field by
 - moves member functions in EditorClientImpl to ChromeClientImpl
 - changes to call SpellChecker function directly rather than via Editor.

BUG=n/a
TEST=n/a; no behavior changes

Review URL: https://codereview.chromium.org/72543005

git-svn-id: svn://svn.chromium.org/blink/trunk@162195 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Make Notification override hasPendingActivity() to prolong its lifetime while async op is running

BUG=none

Review URL: https://codereview.chromium.org/73993003

git-svn-id: svn://svn.chromium.org/blink/trunk@162196 bbb929c8-8fbe-4397-9dbb-9b2b20218538