Add support for multiple frames in SkCodec

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 3f88df5d279f4c6473054c6007bde952c14513f6..09b3b3a6fd4be38ec82fc4dfaf164f8b2d23ec18 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -14,7 +14,6 @@ declare_args() {
   skia_use_expat = true
   skia_use_fontconfig = is_linux
   skia_use_freetype = is_android || is_fuchsia || is_linux
-  skia_use_giflib = !is_fuchsia
   skia_use_libjpeg_turbo = true
   skia_use_libpng = true
   skia_use_libwebp = !is_fuchsia
@@ -338,18 +337,6 @@ optional("fontmgr_fuchsia") {
   ]
 }
 
-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 = []
@@ -504,6 +491,7 @@ component("skia") {
   sources += [
     "src/android/SkBitmapRegionCodec.cpp",
     "src/android/SkBitmapRegionDecoder.cpp",
+    "src/codec/GIFImageDecoder.cpp",
     "src/codec/SkAndroidCodec.cpp",
     "src/codec/SkBmpCodec.cpp",
     "src/codec/SkBmpMaskCodec.cpp",
@@ -511,6 +499,7 @@ component("skia") {
     "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",