Move gif image decoder to SkCodec

skia/BUILD.gn

Index: skia/BUILD.gn
diff --git a/skia/BUILD.gn b/skia/BUILD.gn
index be2084ee18eb358911be02f79577755c8b53d495..33d4d91e9612f9799b02e2e7a19e2953119b75ed 100644
--- a/skia/BUILD.gn
+++ b/skia/BUILD.gn
@@ -29,6 +29,7 @@ config("skia_config") {
     "config",
     "ext",
     "//third_party/skia/include/c",
+    "//third_party/skia/include/codec",
     "//third_party/skia/include/config",
     "//third_party/skia/include/core",
     "//third_party/skia/include/effects",
@@ -92,6 +93,7 @@ config("skia_library_config") {
   include_dirs = [
     "//third_party/skia/include/private",
     "//third_party/skia/include/client/android",
+    "//third_party/skia/src/codec",
     "//third_party/skia/src/core",
     "//third_party/skia/src/image",
     "//third_party/skia/src/opts",
@@ -227,6 +229,7 @@ component("skia") {
   }
 
   # The skia gypi values are relative to the skia_dir, so we need to rebase.
+  sources += skia_codec_sources

[cblume, 2016/12/19 08:04:03]

I had put the required .cpp files inside a Skia build file, which defined
skia_codec_sources.

However, code review comments on that (seen here:
https://skia-review.googlesource.com/c/6205/ ) made it clear that we should
instead have the files be listed out in Chrome.

   sources += skia_core_sources
   sources += skia_effects_sources
   sources += skia_utils_sources