Add the ability to read the chromaticity (cHRM) chunk when png decoding.
Add the ability to read the chromaticity (cHRM) chunk when png decoding.

BUG=
TEST=No uses yet, check compiles.


Review URL: http://codereview.chromium.org/10273024

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@134828 0039d316-1c4b-4281-b951-d872f2087c98

adobe/chromium,adobe/chromium,yitian134/chromium,ropik/chromium,adobe/chromium,adobe/chromium,adobe/chromium,yitian134/chromium,yitian134/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,adobe/chromium,yitian134/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,yitian134/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,ropik/chromium,adobe/chromium,adobe/chromium,yitian134/chromium,ropik/chromium,ropik/chromium,ropik/chromium,ropik/chromium,yitian134/chromium