Rename attribute to "deps"

This hack allows us to support native cc_shared_library aspect
propagation along the "deps" attribute.

See
bazelbuild/bazel#16296 (comment)
for details.

Test: mixed_droid, both at HEAD and after a rollback of the referenced
Bazel commit

Change-Id: I2247b974a5cd7cc105ec1d674569d9eacdbc302b

rules/cc/cc_stub_library.bzl

@@ -153,17 +153,23 @@ def cc_stub_library_shared(name, stubs_symbol_file, version, export_includes, so
         name = name,
         stub_target = name + "_files",
         library_target = name + "_so",
-        root_target = name + "_root",
+        deps = [name + "_root"],
         source_library = source_library,
         tags = tags,
     )
 
 def _cc_stub_library_shared_impl(ctx):
+    # Using a "deps" label_list instead of a single mandatory label attribute
+    # is a hack to support aspect propagation of graph_aspect of the native
+    # cc_shared_library. The aspect will only be applied and propagated along
+    # a label_list attribute named "deps".
+    if len(ctx.attr.deps) != 1:
+        fail("Exactly one 'deps' must be specified for cc_stub_library_shared")
     return [
         ctx.attr.library_target[DefaultInfo],
         ctx.attr.library_target[CcSharedLibraryInfo],
         ctx.attr.stub_target[CcStubInfo],
-        ctx.attr.root_target[CcInfo],
+        ctx.attr.deps[0][CcInfo],
         CcStubLibrariesInfo(has_stubs = True),
         OutputGroupInfo(rule_impl_debug_files = depset()),
         CcStubLibrarySharedInfo(source_library = ctx.attr.source_library),
@@ -175,7 +181,9 @@ _cc_stub_library_shared = rule(
     attrs = {
         "stub_target": attr.label(mandatory = True),
         "library_target": attr.label(mandatory = True),
-        "root_target": attr.label(mandatory = True),
+        # "deps" should be a single element: the root target of the stub library.
+        # See _cc_stub_library_shared_impl comment for explanation.
+        "deps": attr.label_list(mandatory = True),
         "source_library": attr.label(mandatory = True),
     },
 )