GitLab

The CL do:

* Remove the device rect argument from paintDeviceRect because the rectangle can
be calculated from other arguments.

* Remove setByFrame(AndFit) helper functions that are used only once each to simplify
the Viewport class.

* Rename getScreenClipped with getImageBoundsOnScreenClipped. The old name
  sounds it retuns the bounds of screen.

* Add getImageElementBounds to obtain the bounds before applying zoom and
  offset.

BUG=245926
TEST=manually

Review URL: https://codereview.chromium.org/398263002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283719 0039d316-1c4b-4281-b951-d872f2087c98