Fix media metrics reporting float values post crrev.com/84483002

Post the change, reporting metrics fails if passing an array of strings. This CL casts the values to floats before adding them.

BUG=None
NOTRY=true

Review URL: https://codereview.chromium.org/83793013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238157 0039d316-1c4b-4281-b951-d872f2087c98
Media files for media.mse_cases benchmark

BUG=284934
NOTRY=true

Review URL: https://codereview.chromium.org/85403006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238158 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238157
Add clockless video playback perf tests.

BUG=310837

Review URL: https://codereview.chromium.org/86893002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238159 0039d316-1c4b-4281-b951-d872f2087c98
Make const the interface returned by ppb_nacl_private_impl.

After r238083 it was modified to be non-const by mistake and
it should stay const.

This is part of an effort to componentize NaCl code.

BUG=244791

Review URL: https://codereview.chromium.org/99153003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238160 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238159
SVN changes up to revision 238160