Added simple test to compile framework.jar with varying number of internal compilation treads. Added Marker for storing tools information in classes.dex.

Bug:
Change-Id: I53116cf3d796d176d0eae5dc42d92a475bc7c3f2
diff --git a/build.gradle b/build.gradle
index 60357de..e2c21b6 100644
--- a/build.gradle
+++ b/build.gradle
@@ -101,6 +101,7 @@
 
 dependencies {
     compile 'net.sf.jopt-simple:jopt-simple:4.6'
+    compile 'com.googlecode.json-simple:json-simple:1.1.1'
     compile group: 'com.google.guava', name: 'guava', version: '19.0'
     compile group: 'it.unimi.dsi', name: 'fastutil', version: '7.2.0'
     compile group: 'org.apache.commons', name: 'commons-compress', version: '1.12'
@@ -397,6 +398,20 @@
     }
 }
 
+task ExtractMarker(type: Jar) {
+    from sourceSets.main.output
+    baseName 'extractmarker'
+    manifest {
+      attributes 'Main-Class': 'com.android.tools.r8.ExtractMarker'
+    }
+    // In order to build without dependencies, pass the exclude_deps property using:
+    // gradle -Pexclude_deps ExtractMarker
+    if (!project.hasProperty('exclude_deps')) {
+        // Also include dependencies
+        from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
+    }
+}
+
 task sourceJar(type: Jar, dependsOn: classes) {
     classifier = 'src'
     from sourceSets.main.allSource