remove omx_sink and buffer merge

Remove OmxSink interface because Buffer Allocation will go through Allocator in the future, and all allocation required parameters will be passed to "Allocator factory" during intiailized phase of render/decoder. 
Remove OMX_BUFFERHEADERTYPE merge logic, this is based on assumptions that all vendor will use one frame per buffer scheme instead of one slice(multiple rows) per buffer which is specified by OpenMAX IL Spec.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=45705

[jiesun, 2010-04-26 17:40:56]

remove omx_sink logic
remove merge omx buffer for one frame.
some logic is temporary due to transition.

[Alpha Left Google, 2010-04-26 22:46:23]

On 2010/04/26 17:40:56, jiesun wrote:
> remove omx_sink logic
> remove merge omx buffer for one frame.
> some logic is temporary due to transition.

LGTM. Just change the name of the buffer types, can also be done later.

[wjia(left Chromium), 2010-04-27 00:15:42]

LGTM.