First step of new component updater on-demand framework: direct API.

This is the first in a series of CLs to implement the new on-demand
framework for the component update service. I've temporarily
'friended' the PNaCl installer so that I can make those changes in a
separate changelist; once we reach consensus on the triggering
mechanism.

This is a re-upload of issue 27000013.

BUG=307193

Review URL: https://codereview.chromium.org/37943003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231192 0039d316-1c4b-4281-b951-d872f2087c98
Using largest favicon for shortcut when possible.

The icon will be fetched as
1. The largest favicon which is not smaller than platform's launch icon.
2. The largest icon among all icons.

BUG=298446

Review URL: https://codereview.chromium.org/38523002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231194 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 231192
Native bindinds for chrome.webrtc extensions APIs

Adding native bindings for cast extension APIs defined under in
chrome.webrtc.

Also updated chrome.webrtc APIs to the latest version.

BUG=301920

Review URL: https://codereview.chromium.org/41433002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231196 0039d316-1c4b-4281-b951-d872f2087c98
Extract supported codecs from CDM component manifest.

Look for "x-cdm-codecs" in the manifest and set its value in
WebPluginInfo::WebPluginMimeType::additional_param_* where it can be used to
determine the types supported.

The manifest is read when registering existing components in addition to new
installs so that the manifest information is always available.

Also updated the non-component path so the behavior is consistent for the
consumer, which will be updated in a separate CL.

BUG=311370
TEST=canPlayType() with various manifest configurations

Review URL: https://codereview.chromium.org/42003002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231197 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 231196
SVN changes up to revision 231197