Add SkBitmap StructTraits for skia::mojo::Bitmap.

mojo/public/tools/bindings/mojom.gni

Index: mojo/public/tools/bindings/mojom.gni
diff --git a/mojo/public/tools/bindings/mojom.gni b/mojo/public/tools/bindings/mojom.gni
index 543c18775fa4ecc36f868711c5151c8190a3e4a1..791582cd6ee1f53545957fba0f9927f885d27cd2 100644
--- a/mojo/public/tools/bindings/mojom.gni
+++ b/mojo/public/tools/bindings/mojom.gni
@@ -321,7 +321,7 @@ template("mojom") {
         # //mojo/something:something and we can append cpp_sources_suffix to
         # get the cpp dependency name.
         full_name = get_label_info("$d", "label_no_toolchain")
-        deps += [ "${full_name}${variant_suffix}_${cpp_sources_suffix}" ]
+        public_deps += [ "${full_name}${variant_suffix}_${cpp_sources_suffix}" ]
       }
       foreach(typemap, active_typemaps) {
         if (defined(typemap.public_headers)) {
@@ -333,6 +333,9 @@ template("mojom") {
         if (defined(typemap.sources)) {
           sources += typemap.sources
         }
+        if (defined(typemap.public_deps)) {
+          public_deps += typemap.public_deps
+        }
         if (defined(typemap.deps)) {
           deps += typemap.deps
         }