valgrind: add suppression for image decoder test leaks
valgrind: add suppression for image decoder test leaks

BUG=37727
TEST=tools/valgrind/chrome_tests.sh -t test_shell --gtest_filter=BMPImageDecoderTest.DecodingFast:ICOImageDecoderTest.Decoding:ICOImageDecoderTest.ImageNonZeroFrameIndex

Review URL: http://codereview.chromium.org/690001

git-svn-id: http://src.chromium.org/svn/trunk/src@40983 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 34a067c364720b1d58db5c28055039ea02603b6f
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser