Buildbot spec and gyp defs for SK_USE_DISCARDABLE_SCALEDIMAGECACHE bot

tools/buildbot_spec.py

 #
 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 
 #!/usr/bin/env python
 
 usage = '''
@@ skipping 293 matching lines @@
         'Build-Ubuntu-GCC-x86_64-Debug-CrOS_Link',
         'Build-Ubuntu-GCC-x86_64-Release-Mesa',
         'Housekeeper-PerCommit',
         'Perf-Win8-MSVC-ShuttleB-GPU-HD4600-x86_64-Release-Trybot',
         'Perf-Android-GCC-Nexus5-GPU-Adreno330-Arm7-Release-Appurify',
         'Test-Android-GCC-Nexus6-GPU-Adreno420-Arm7-Debug',
         'Test-ChromeOS-GCC-Link-CPU-AVX-x86_64-Debug',
         'Test-iOS-Clang-iPad4-GPU-SGX554-Arm7-Debug',
         'Test-Mac10.8-Clang-MacMini4.1-GPU-GeForce320M-x86_64-Release',
         'Test-Ubuntu-Clang-GCE-CPU-AVX2-x86_64-Coverage',
+        ('Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-'
+         'SK_USE_DISCARDABLE_SCALEDIMAGECACHE'),
         'Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD',
         'Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-Shared',
         'Test-Ubuntu-GCC-ShuttleA-GPU-GTX550Ti-x86_64-Release-Valgrind',
         'Test-Win8-MSVC-ShuttleB-GPU-HD4600-x86-Release-ANGLE',
         'Test-Win8-MSVC-ShuttleA-CPU-AVX-x86_64-Debug',
   ]
 
   cov = coverage.coverage()
   cov.start()
   for case in cases:
@@ skipping 17 matching lines @@
   if len(sys.argv) == 2 and sys.argv[1] == 'test':
     self_test()
     sys.exit(0)
 
   if len(sys.argv) != 3:
     print usage
     sys.exit(1)
 
   with open(sys.argv[1], 'w') as out:
     json.dump(get_builder_spec(sys.argv[2]), out)