Implementation of chrome.cast.channel in insecure mode.

BUG=295843

Review URL: https://codereview.chromium.org/23576019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227345 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227345
Run strip via xcrun.

In Xcode 5, strip is no longer in SYSTEM_DEVELOPER_BIN_DIR. It is only in
DT_TOOLCHAIN_DIR. I also checked Xcode 4.6.1 and found that DT_TOOLCHAIN_DIR
was also set there, and strip is in both SYSTEM_DEVELOPER_BIN_DIR and
DT_TOOLCHAIN_DIR in that version.

Environment variables as set when Xcode is installed at /Applications/Xcode.app:

SYSTEM_DEVELOPER_BIN_DIR=/Applications/Xcode.app/Contents/Developer/usr/bin
DT_TOOLCHAIN_DIR=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefa
ult.xctoolchain

xcrun should be able to find strip without having to resort to manual
environment interpretation.

R=thakis@chromium.org

Review URL: https://codereview.chromium.org/24352006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227347 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227347