Checkpoint work to get GN builds working on Android.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 445f837442465d48896794d5fece4172af4c2d73..abdbc45fb37c148dca54d3c80a12b0f581a77070 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -48,7 +48,7 @@ group("root") {
     "//url",
   ]
 
-  if (is_posix) {  # TODO(brettw) should be use_openssl
+  if (is_posix && !is_android) {  # TODO(brettw) should be use_openssl
     deps += [
       "//third_party/openssl",
     ]
@@ -58,4 +58,14 @@ group("root") {
       "//third_party/freetype2",
     ]
   }
+
+  if (is_android) {
+    deps -= [
+      "//skia",
+      "//third_party/libusb",
+      "//tools/gn",
+      "//ui/events",
+      "//ui/gfx",
+    ]
+  }
 }