lint support.

Bug: 6167394
$make lint-<app-name>       # to lint on a single module
$make lintall               # to lint on all packages in the source
                              tree.

Change-Id: I4decc76fb75793ce44809232b0ec72b766fbb434
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index f3929ad..ef0b031 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -125,6 +125,7 @@
 # Whether to keep the generated R/Manifest classes when building static Java library
 # with Android resource. false(default), or true
 LOCAL_KEEP_R_CLASS_IN_STATIC_JAVA_LIBRARY:=
+LOCAL_LINT_FLAGS:=
 
 # Trim MAKEFILE_LIST so that $(call my-dir) doesn't need to
 # iterate over thousands of entries every time.