Have Gradle permit SL to be an included build

Bug: 72121179
Test: ./gradlew projects
Test: make another project whose settings.gradle applies
      include-builds.gradle , and build that project too

Change-Id: I860e85560e79e02120143c86a963f3769897dac8

diff --git a/include-composite-deps.gradle b/include-composite-deps.gradle
new file mode 100644
index 0000000..c8a795f
--- /dev/null
+++ b/include-composite-deps.gradle

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+// This file is part of a a workaround for https://github.com/gradle/gradle/issues/1909 to enable
+// including this Support Library build as an included build. See include-support-library.gradle
+// for usage instructions.
+
+boolean currentBuildIsRootBuild = (gradle.parent == null)
+
+// Add included builds. This only works if this is currently the root build, so this script should
+// be applied to several builds and will only enable itself when part of the root build.
+if (currentBuildIsRootBuild) {
+  String buildScriptDir = buildscript.sourceFile.parent
+  File externalRoot = new File(buildScriptDir, '../../external')
+
+  includeBuild(new File(externalRoot, 'doclava'))
+  includeBuild(new File(externalRoot, 'jdiff'))
+}
+
+