Aura on Android: compile gn target extensions/browser.

device/usb/BUILD.gn

Index: device/usb/BUILD.gn
diff --git a/device/usb/BUILD.gn b/device/usb/BUILD.gn
index c30ae56e500287be62767bb69e5106600a5f36a4..8a9f47f78786249dddb20b845e858dc44772fb36 100644
--- a/device/usb/BUILD.gn
+++ b/device/usb/BUILD.gn
@@ -4,7 +4,7 @@
 
 import("//build/config/features.gni")
 
-assert(!is_android && !is_ios)
+assert(!is_ios)
 
 source_ids = "//third_party/usb_ids/usb.ids"
 generated_ids = "$target_gen_dir/usb_ids_gen.cc"
@@ -57,6 +57,11 @@ source_set("usb") {
       "//dbus",
     ]
   }
+
+  # TODO(moshayedi): crbug.com/549257. Add USB support for Aura on Android.
+  if (is_android) {
+    deps -= [ "//third_party/libusb" ]
+  }
 }
 
 source_set("mocks") {