Remove calls to new when modifying shader constants.

There were some unnecessary temporary copies we can remove, and the rest have a maximum size so we can allocate them on the stack.

BUG=276
TEST=

Review URL: https://codereview.appspot.com/5540071

git-svn-id: http://angleproject.googlecode.com/svn/trunk@961 736b8ea6-26fd-11df-bfd4-992fa37f6226
3 files changed