Add a QuicSustainedBandwidthEstimator class. Not yet used.

Add a QuicSustainedBandwidthEstimator class. Not yet used.

Followup CL (internal change: 72831442) in progress (not ready for
review, but in case you want to see intended usage) which does the
following:

1) Use this in the QuicSentPacketManager.
2) Detect substantial differences between subsequent sustained bandwidth
   estimates.
3) Send estimates to client in server config update.

Merge internal change: 73132177

R=rch@chromium.org

[ramant (doing other things), 2014-08-15 02:35:35]

https://codereview.chromium.org/477053002/diff/1/net/quic/quic_sustained_band...
File net/quic/quic_sustained_bandwidth_recorder.h (right):

https://codereview.chromium.org/477053002/diff/1/net/quic/quic_sustained_band...
net/quic/quic_sustained_bandwidth_recorder.h:46: int32 MaxBandwidthTimestamp()
const {
rjshade@: should we use int64 instead of int32?

[Robbie Shade, 2014-08-15 12:08:38]

https://codereview.chromium.org/477053002/diff/1/net/quic/quic_sustained_band...
File net/quic/quic_sustained_bandwidth_recorder.h (right):

https://codereview.chromium.org/477053002/diff/1/net/quic/quic_sustained_band...
net/quic/quic_sustained_bandwidth_recorder.h:46: int32 MaxBandwidthTimestamp()
const {
On 2014/08/15 02:35:35, ramant wrote:
> rjshade@: should we use int64 instead of int32?

Yep, thanks!

[Ryan Hamilton, 2014-08-15 14:38:48]

lgtm

[ramant (doing other things), 2014-08-15 17:54:18]

https://codereview.chromium.org/477053002/diff/1/net/quic/quic_sustained_band...
File net/quic/quic_sustained_bandwidth_recorder.h (right):

https://codereview.chromium.org/477053002/diff/1/net/quic/quic_sustained_band...
net/quic/quic_sustained_bandwidth_recorder.h:46: int32 MaxBandwidthTimestamp()
const {
On 2014/08/15 12:08:38, Robbie Shade wrote:
> On 2014/08/15 02:35:35, ramant wrote:
> > rjshade@: should we use int64 instead of int32?
> 
> Yep, thanks!

Great. Will submit the change to the internal source tree first.

thanks
raman