After removing the legacy Wave capture implementation, we're seeing
frequent failures on Windows due to "FORMAT_NOT_SUPPORTED".
It seems we still have places that hardcode a specific sample rate instead of querying.
This CL adds basic support for resampling to see how much that buys us while we track down the code that still requires this.
Notably we don't support cases where there are mismatches in the number of channels etc,
so there will possibly still be cases where a user has a mono mic but the calling code has hardcoded requiring stereo input.

BUG=684741
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2690793002
Cr-Commit-Position: refs/heads/master@{#451461}