[Title] High Bit Rate of HTML5 streaming video are unsmooth and stuck during playing

[Title] High Bit Rate of HTML5 streaming video are unsmooth and stuck during playing
[Issue#] TD-6970
[Problem] When the bandwidth (Bit Rate) of video source bigger than 2560 kbps,
        (depends on the type of codec and reference frame size), the playback would
	be unsmooth and even stuck.
[Cause] The pop ring-cache head operation happened while overflow the 0.99 of Max Cache
	-> 2MB, but the high bit rate of video would need much more free cache space.
[Solution] Supports some HD video source achieve more than 4096 kbps, extend the default
        max cache size to 5MB limition tmpfs and recover percentage from 99% to 69%.

        This updates will not impact the manual media-pipeline setup, because the pipeline owner c
        set any propriety as before.
[Developer] Qing.Zhang (qing.zhang@intel.com)