Enable WebAudio support on Android/x86.

WebAudio support itself is disabled by default and can be enabled
using a flag in chrome://flags.  When so enabled, WebAudio will run.

BUG=290622,292922

Review URL: https://codereview.chromium.org/79193003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239518 0039d316-1c4b-4281-b951-d872f2087c98
Reserve 100 more ids for autocomplete dynamic field trials.

BUG=

Review URL: https://codereview.chromium.org/100993003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239519 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239519
Use schemas bundled in extensions to convert policies loaded on Windows.

Extensions that support policies must declare those policies in a JSON
schema. All the policy providers get a mapping from components to their
schemas. This change makes the Windows policy provider use those schemas
when loading policies from GPO or the registry.

The previous behavior was to load the schema from GPO/the registry too;
this behavior is still used if the extension doesn't include a schema,
to support the Legacy Browser Support extension for the next releases.

BUG=108994, 108992

Review URL: https://codereview.chromium.org/102493002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239520 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239520