Break Sky's dependency on cc

sky/viewer/BUILD.gn

Index: sky/viewer/BUILD.gn
diff --git a/sky/viewer/BUILD.gn b/sky/viewer/BUILD.gn
index f0d19917890744ea222b29193960860a90374392..0887e97a2e03755b16195a8b598c01888a0d6a90 100644
--- a/sky/viewer/BUILD.gn
+++ b/sky/viewer/BUILD.gn
@@ -23,8 +23,6 @@ mojo_native_application("viewer") {
     "internals.h",
     "platform/platform_impl.cc",
     "platform/platform_impl.h",
-    "platform/weblayertreeview_impl.cc",
-    "platform/weblayertreeview_impl.h",
     "platform/weburlloader_impl.cc",
     "platform/weburlloader_impl.h",
     "script/script_runner.cc",
@@ -42,11 +40,8 @@ mojo_native_application("viewer") {
     ":bindings",
     ":sky_modules",
     "//base:i18n",
-    "//cc",
-    "//cc/surfaces",
     "//gin",
     "//mojo/application",
-    "//mojo/cc",
     "//mojo/common",
     "//mojo/converters/geometry",
     "//mojo/converters/surfaces",
@@ -70,7 +65,6 @@ mojo_native_application("viewer") {
     "//sky/engine/v8_inspector",
     "//sky/services/inspector:bindings",
     "//sky/services/testing:bindings",
-    "//sky/viewer/cc",
     "//third_party/icu",
     "//ui/native_theme",
     "//url",