Assume FrameView::m_frame is never NULL

Assume FrameView::m_frame is never NULL

FrameView::clearFrame() is unused and we never pass a null frame pointer to FrameView::create(),
so FrameView::m_frame should never be NULL. This removes FrameView::clearFrame() and
removes m_frame check from conditional expressions.

BUG=
R=abarth@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=157068

[abarth-chromium, 2013-08-31 05:58:30]

LGTM

Please consider making FrameView::frame return a reference rather than a
pointer.  :)

[caseq, 2013-09-02 08:08:43]

Committed patchset #1 manually as r157068 (presubmit successful).

[caseq, 2013-09-02 08:38:13]

On 2013/08/31 05:58:30, abarth wrote:
> LGTM
> 
> Please consider making FrameView::frame return a reference rather than a
> pointer.  :)

Sure! It's somewhat bigger, though, so extracting it to a separate CL:
https://codereview.chromium.org/23728003