Set m_pos as private in InlineIterator, and use getter and setter functions

InlineIterator has been exported m_pos as public directly though it is member variable.
This patch set it as private, and add getter/setter functions for it.

Merge from WebKit r161085.

BUG=N/A

Review URL: https://codereview.chromium.org/120493004

git-svn-id: svn://svn.chromium.org/blink/trunk@164374 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Fixed profiler warning icon overlapping.

R=apavlov
NOTRY=true

Review URL: https://codereview.chromium.org/120683003

git-svn-id: svn://svn.chromium.org/blink/trunk@164375 bbb929c8-8fbe-4397-9dbb-9b2b20218538