Merge 168106 - Reduce high latency input buffers to 1.

Merge 168106 - Reduce high latency input buffers to 1.

Multiple buffers lead to trampling input data which is in the process
of being transmitted across the shared memory.

Since this API was never intended for low latency usage, clients should
instead use a larger buffer size. At least 2048 @ 44.1kHz (Flash) and
1600 at 16kHz (speech recognizer).

vtl will land a fix to flash along side this change to move it off of the
RecommendSampleCount() method to a hard coded 2048 frame buffer.

NOTRY=true
BUG=157613
TEST=input is clear and crisp w/ flash @ 2048 buffer.

Review URL: https://codereview.chromium.org/11418017

TBR=dalecurtis@google.com
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=170321