Staging for cleanup of SkPicture-related headers

gyp/common_conditions.gypi

 # conditions used in both common.gypi and skia.gyp in chromium
 #
 {
   'defines': [
     'SK_ALLOW_STATIC_GLOBAL_INITIALIZERS=<(skia_static_initializers)',
     'SK_SUPPORT_GPU=<(skia_gpu)',
     'SK_SUPPORT_OPENCL=<(skia_opencl)',
     'SK_FORCE_DISTANCEFIELD_FONTS=<(skia_force_distancefield_fonts)',
   ],
   'conditions' : [
@@ skipping 280 matching lines @@
         # FIXME: b/13729784: Need to rework LayerRasterizer.cpp
         'SK_SUPPORT_LEGACY_LAYERRASTERIZER_API',
         # Temporary until https:#googleplex-android-review.git.corp.google.com/#/c/442220/
         # lands.
         'SK_SUPPORT_LEGACY_GETTOTALCLIP',
         # Still need to switch Android to the new name for N32.
         'kNative_8888_SkColorType kN32_SkColorType',
         'SK_SUPPORT_LEGACY_PICTURE_CAN_RECORD',
         'SK_SUPPORT_DEPRECATED_RECORD_FLAGS',
         'SK_SUPPORT_LEGACY_DERIVED_PICTURE_CLASSES',
+        'SK_SUPPORT_LEGACY_PICTURE_HEADERS',
         'SK_SUPPORT_LEGACY_BLURDRAWLOOPERCONSTRUCTORS',
       ],
     }],
 
     [ 'skia_os in ["linux", "freebsd", "openbsd", "solaris", "nacl", "chromeos"]',
       {
         'defines': [
           'SK_SAMPLES_FOR_X',
           'SK_BUILD_FOR_UNIX',
         ],
@@ skipping 295 matching lines @@
       'defines': [
         'SK_USE_POSIX_THREADS',
       ],
     }],
   ], # end 'conditions'
   # The Xcode SYMROOT must be at the root. See build/common.gypi in chromium for more details
   'xcode_settings': {
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }