[Cronet] Use gn desc deps to find third_party licenses.

components/BUILD.gn

Index: components/BUILD.gn
diff --git a/components/BUILD.gn b/components/BUILD.gn
index 13f0c62acd2090e44ae9b49040a0a7ddd880a678..67cb68c508f14329f5864fc2b81053b0a975060c 100644
--- a/components/BUILD.gn
+++ b/components/BUILD.gn
@@ -15,6 +15,14 @@ if (is_ios) {
   import("//ios/build/config.gni")
 }
 
+group("cronet") {
+  if (is_ios) {
+    deps = [
+      "//components/cronet/ios:cronet_package",

[brettw, 2016/05/03 22:13:03]

I'd actually put this in the root build file. You can add it to the condition in
both_gn_and_gyp or something (whatever is appropriate, shouldn't need a new
target).

[mef, 2016/05/11 15:57:27]

Done.

+    ]
+  }
+}
+
 if (is_ios || is_mac) {
   bundle_data("components_tests_pak_bundle_data") {
     public_deps = [