Add gyp and gn targets for jFormatString.jar needed by errorprone.

BUG=
R=jbudorick@chromium.org

Review URL: https://codereview.chromium.org/1309983003 .
diff --git a/BUILD.gn b/BUILD.gn
new file mode 100644
index 0000000..eb1b297
--- /dev/null
+++ b/BUILD.gn
@@ -0,0 +1,10 @@
+# Copyright 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/android/rules.gni")
+
+# GYP: //third_party/findbugs:format_string_jar
+java_prebuilt("format_string_java") {
+  jar_path = "lib/jFormatString.jar"
+}
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diff --git a/README.chromium b/README.chromium
index 77e145a..c117d9f 100644
--- a/README.chromium
+++ b/README.chromium
@@ -7,4 +7,5 @@
 License File: LICENSE
 
 Local Modifications:
+- Added gn and gyp targets for lib/jFormatString.jar.
 - Set the svn:executable bit correctly on bin/findbugs.bat and bin/findbugs.ico.
diff --git a/findbugs.gyp b/findbugs.gyp
new file mode 100644
index 0000000..584f123
--- /dev/null
+++ b/findbugs.gyp
@@ -0,0 +1,19 @@
+# Copyright 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'targets': [
+    {
+      # GN: //third_party/findbugs:format_string_java
+      'target_name': 'format_string_jar',
+      'type': 'none',
+      'variables': {
+        'jar_path': 'lib/jFormatString.jar',
+      },
+      'includes': [
+        '../../build/host_prebuilt_jar.gypi',
+      ]
+    },
+  ]
+}
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