Add generate_jni template

This adds a template for using the jni_generator. Creates the
base_jni_headers target and updates the base target to depend on it and
actually use the sources that required it.

Adds //third_party/android_tools:cpu_features required by one of the
base files that also required jni.

Disable a bunch of third_party targets for Android builds.

BUG=359249

Review URL: https://codereview.chromium.org/237973002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@264695 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/BUILD.gn b/BUILD.gn
index 3899b0a6..2e3799e 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -56,6 +56,8 @@
 
   if (is_android) {
     deps -= [
+      "//crypto",
+      "//net",
       "//skia",
       "//third_party/libusb",
       "//tools/gn",