Don't include _unittest.py files in `grit_info --inputs` output.
Don't include _unittest.py files in `grit_info --inputs` output.

If only a test changes, it shouldn't affect the files created by grit, so
this is useless output.

Reduces the size of chrome's ninja files by about 120kB / 1%.

Review URL: https://codereview.chromium.org/125353002/


git-svn-id: 50c90c531a9fd8f38831f054b7ea6b96f50d91dc@144 7262f16d-afe8-6277-6482-052fa10e57b1

bpsinc-native/src_tools_grit,bpsinc-native/src_tools_grit,android-ia/platform_external_chromium_org_tools_grit,Omegaphora/external_chromium_org_tools_grit,android-ia/platform_external_chromium_org_tools_grit,Omegaphora/external_chromium_org_tools_grit,geekboxzone/lollipop_external_chromium_org_tools_grit,geekboxzone/lollipop_external_chromium_org_tools_grit,AOSPU/external_chromium_org_tools_grit,xin3liang/platform_external_chromium_org_tools_grit