Cast:Splitting rtcp sender

Moving sender packet building code into the net/rtcp folder. 
Namespaces and renaming will be added in a follow up cl for
the entire folder.

BUG=327482

Review URL: https://codereview.chromium.org/102413014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241965 0039d316-1c4b-4281-b951-d872f2087c98
Populate GestureScrollBegin hint properties in Aura

When a touchscreen scroll beings in Aura, keep track of how much movement
was involved in each direction in order to triger the scroll.

BUG=321643

Review URL: https://codereview.chromium.org/107053003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241966 0039d316-1c4b-4281-b951-d872f2087c98
Make extension Reference link in chrome_sidenav.json point to api_index.html
not whats_new.html.

R=jyasskin@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/108303012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241967 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241966
SVN changes up to revision 241967