Add support for multiple frames in SkCodec

BUILD.gn

 # Copyright 2016 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("gn/shared_sources.gni")
 
 if (!defined(is_skia_standalone)) {
   is_skia_standalone = false
 }
 
 declare_args() {
   skia_use_angle = false
   skia_use_expat = true
   skia_use_fontconfig = is_linux
   skia_use_freetype = is_android || is_fuchsia || is_linux
   skia_use_gdi = false
-  skia_use_giflib = !is_fuchsia
   skia_use_libjpeg_turbo = true
   skia_use_libpng = true
   skia_use_libwebp = !is_fuchsia
   skia_use_mesa = false
   skia_use_sfntly = !is_fuchsia && !is_win  # TODO: icu on Windows, re-enable this.
   skia_use_vulkan = is_android && defined(ndk_api) && ndk_api >= 24
   skia_use_zlib = true
 
   skia_enable_android_framework_defines = false
   skia_enable_gpu = true
@@ skipping 312 matching lines @@
 
   deps = [
     "//third_party/freetype2",
   ]
   sources = [
     "src/ports/SkFontMgr_custom.cpp",
     "src/ports/SkFontMgr_custom_empty_factory.cpp",
   ]
 }
 
-optional("gif") {
-  enabled = skia_use_giflib
-  public_defines = [ "SK_HAS_GIF_LIBRARY" ]
-
-  deps = [
-    "//third_party/giflib",
-  ]
-  sources = [
-    "src/codec/SkGifCodec.cpp",
-  ]
-}
-
 optional("gpu") {
   enabled = skia_enable_gpu
   public_defines = []
 
   sources = skia_gpu_sources + [ "src/gpu/gl/GrGLDefaultInterface_native.cpp" ]
 
   # These paths need to be absolute to match the ones produced by shared_sources.gni.
   sources -= get_path_info([
                              "src/gpu/gl/GrGLCreateNativeInterface_none.cpp",
                              "src/gpu/gl/GrGLDefaultInterface_none.cpp",
@@ skipping 113 matching lines @@
   deps = [
     ":arm64",
     ":armv7",
     ":avx",
     ":crc32",
     ":dsp",
     ":fontmgr_android",
     ":fontmgr_custom",
     ":fontmgr_fontconfig",
     ":fontmgr_fuchsia",
-    ":gif",
     ":gpu",
     ":hsw",
     ":jpeg",
     ":none",
     ":pdf",
     ":png",
     ":sse2",
     ":sse41",
     ":sse42",
     ":ssse3",
     ":typeface_freetype",
     ":webp",
     ":xml",
   ]
 
   sources = []
   sources += skia_core_sources
   sources += skia_effects_sources
   sources += skia_sksl_sources
   sources += skia_utils_sources
   sources += [
     "src/android/SkBitmapRegionCodec.cpp",
     "src/android/SkBitmapRegionDecoder.cpp",
+    "src/codec/GIFImageReader.cpp",
     "src/codec/SkAndroidCodec.cpp",
     "src/codec/SkBmpCodec.cpp",
     "src/codec/SkBmpMaskCodec.cpp",
     "src/codec/SkBmpRLECodec.cpp",
     "src/codec/SkBmpStandardCodec.cpp",
     "src/codec/SkCodec.cpp",
     "src/codec/SkCodecImageGenerator.cpp",
+    "src/codec/SkGifCodec.cpp",
     "src/codec/SkMaskSwizzler.cpp",
     "src/codec/SkMasks.cpp",
     "src/codec/SkSampledCodec.cpp",
     "src/codec/SkSampler.cpp",
+    "src/codec/SkStreamBuffer.cpp",
     "src/codec/SkSwizzler.cpp",
     "src/codec/SkWbmpCodec.cpp",
     "src/images/SkImageEncoder.cpp",
     "src/images/SkImageEncoder_Factory.cpp",
     "src/images/SkKTXImageEncoder.cpp",
     "src/ports/SkDiscardableMemory_none.cpp",
     "src/ports/SkGlobalInitialization_default.cpp",
     "src/ports/SkImageGenerator_skia.cpp",
     "src/ports/SkMemory_malloc.cpp",
     "src/ports/SkOSFile_stdio.cpp",
@@ skipping 271 matching lines @@
                            [
                              "*.c*",
                              rebase_path("gm"),
                            ],
                            "list lines",
                            [])
   test_lib("gm") {
     public_include_dirs = [ "gm" ]
     sources = gm_sources
     deps = [
+      ":flags",
       ":gpu_tool_utils",
       ":skia",
       ":tool_utils",
     ]
   }
 
   tests_sources = exec_script("gyp/find.py",
                               [
                                 "*.c*",
                                 rebase_path("tests"),
@@ skipping 391 matching lines @@
         ":samples",
         ":skia",
         ":tool_utils",
         ":views",
         "//third_party/jsoncpp",
       ]
       testonly = true
     }
   }
 }