Support `public_deps` in `android_library`

build/config/android/rules.gni

Index: build/config/android/rules.gni
diff --git a/build/config/android/rules.gni b/build/config/android/rules.gni
index 075c8a77c29be4a5903b7072b000ba6d7d4182b5..6e38320e69e21805b361a8d86432657b85f0249d 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -1204,6 +1204,9 @@ if (enable_java_templates) {
   #   deps: Specifies the dependencies of this target. Java targets in this list
   #     will be added to the javac classpath. Android resources in dependencies
   #     will be used when building this library.
+  #   public_deps: Specifies the dependencies of this target that will be
+  #     exposed as part of its public API (the .class files will be available
+  #     in the output jar).
   #
   #   java_files: List of .java files included in this library.
   #   srcjar_deps: List of srcjar dependencies. The .java files in the srcjars
@@ -1269,9 +1272,32 @@ if (enable_java_templates) {
       assert(defined(invoker.alternative_android_sdk_ijar_dep))
     }
 
-    java_library_impl(target_name) {
+    _java_library_impl_target_name = target_name
+    _needs_dist_jar = false
+
+    if (defined(invoker.public_deps)) {
+      forward_variables_from(invoker, [ "testonly" ])
+
+      _public_deps = invoker.public_deps
+      _java_library_impl_target_name = "${target_name}__java_library_impl"
+      _public_deps += [ ":${_java_library_impl_target_name}" ]
+      _needs_dist_jar = true
+
+      dist_jar(target_name) {
+        _target_dir_name = get_label_info(":$target_name", "dir")
+        output_jar_path =
+            "$root_out_dir/lib.java$_target_dir_name/${target_name}.jar"
+        deps = _public_deps
+      }
+    }
+
+    java_library_impl(_java_library_impl_target_name) {
       forward_variables_from(invoker, "*")
 
+      if (_needs_dist_jar) {
+        output_name = "${target_name}_no_public_deps"
+      }
+
       supports_android = true
       requires_android = true