Add GN build for parts of gpu and ozone.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 38648cd5be69f04f2c96ffbf769184c23ec9b695..e5e8dd3ed7b13402daef242cbff0e025f38c9229 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -32,6 +32,7 @@ group("root") {
     "//crypto",
     "//device/usb",
     #"//extensions/common/api:extensions_api",
+    "//gpu:gles2_c_lib",
     "//ipc",
     "//mojo",
     "//net",
@@ -73,8 +74,9 @@ group("root") {
     deps -= [
       "//components/os_crypt",
       "//crypto",
+      "//gpu:gles2_c_lib",  # Needs Skia.
       "//net",
-      "//skia",
+      "//skia",  # Needs some ARM stuff
       "//third_party/libusb",
       "//third_party/WebKit/Source/wtf",  # TODO(brettw) re-enable for Android.
       "//tools/gn",