The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a6ae8f1581edf00b8a2c8b1839aaa18a448cb8d8

commit a6ae8f1581edf00b8a2c8b1839aaa18a448cb8d8
Author: Guido Urdaneta <guidou@chromium.org>
Date: Wed Oct 17 12:03:39 2018

Improve handling of frameRate MediaStream constrainable property.

This CL:
- Removes the restriction of frame rates to no less than 1Hz.
  This limit is a remnant from the old constraints processing
  algorithm. There is no reason to keep this restriction,
  especially because applyConstraints did not have any lower limit.
- Use a new minimum frame rate of numeric_limits<float>::min(),
  equivalent to allowing any positive value and enforce it in
  both getUserMedia() and applyConstraints(). Prior to this,
  applyConstraints allowed zero and ideal negative values. Zero
  was interpreted by VideoTrackAdapter to mean the native frame
  rate of the source, and negative values caused a renderer crash
  due to a CHECK in VideoTrackAdapter.

This CL also serves as preparation for support for the frameRate
constrainable property.

Bug:  814131 , 854980 
Change-Id: I7f45fe2862f636100d408a136fe5038fe0994afb
Reviewed-on: https://chromium-review.googlesource.com/c/1276506
Reviewed-by: Henrik Boström <hbos@chromium.org>
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600354}
[modify] https://crrev.com/a6ae8f1581edf00b8a2c8b1839aaa18a448cb8d8/content/renderer/media/stream/media_stream_constraints_util.cc
[modify] https://crrev.com/a6ae8f1581edf00b8a2c8b1839aaa18a448cb8d8/content/renderer/media/stream/media_stream_constraints_util.h
[modify] https://crrev.com/a6ae8f1581edf00b8a2c8b1839aaa18a448cb8d8/content/renderer/media/stream/media_stream_constraints_util_video_device.cc
[modify] https://crrev.com/a6ae8f1581edf00b8a2c8b1839aaa18a448cb8d8/content/renderer/media/stream/media_stream_constraints_util_video_device_unittest.cc