Revert of Revert of [Android] JUnit runner + gyp changes.

testing/android/junit/java/src/org/chromium/testing/local/JunitTestMain.java

Index: testing/android/junit/java/src/org/chromium/testing/local/JunitTestMain.java
diff --git a/testing/android/junit/java/src/org/chromium/testing/local/JunitTestMain.java b/testing/android/junit/java/src/org/chromium/testing/local/JunitTestMain.java
new file mode 100644
index 0000000000000000000000000000000000000000..d9c468d8470d5af2da99df76bb70f1ba043a69cf
--- /dev/null
+++ b/testing/android/junit/java/src/org/chromium/testing/local/JunitTestMain.java
@@ -0,0 +1,96 @@
+// Copyright 2014 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.
+
+package org.chromium.testing.local;
+
+import org.junit.runner.JUnitCore;
+import org.junit.runner.Request;
+import org.junit.runner.RunWith;
+
+import java.io.IOException;
+import java.util.Enumeration;
+import java.util.LinkedList;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+import java.util.regex.Pattern;
+
+/**
+ *  Runs tests based on JUnit from the classpath on the host JVM based on the
+ *  provided filter configurations.
+ */
+public final class JunitTestMain {
+
+    private static final String CLASS_FILE_EXT = ".class";
+
+    private static final Pattern COLON = Pattern.compile(":");
+    private static final Pattern FORWARD_SLASH = Pattern.compile("/");
+
+    private JunitTestMain() {
+    }
+
+    /**
+     *  Finds all classes on the class path annotated with RunWith.
+     */
+    public static Class[] findClassesFromClasspath() {
+        String[] jarPaths = COLON.split(System.getProperty("java.class.path"));
+        LinkedList<Class> classes = new LinkedList<Class>();
+        for (String jp : jarPaths) {
+            try {
+                JarFile jf = new JarFile(jp);
+                for (Enumeration<JarEntry> eje = jf.entries(); eje.hasMoreElements();) {
+                    JarEntry je = eje.nextElement();
+                    String cn = je.getName();
+                    if (!cn.endsWith(CLASS_FILE_EXT) || cn.indexOf('$') != -1) {
+                        continue;
+                    }
+                    cn = cn.substring(0, cn.length() - CLASS_FILE_EXT.length());
+                    cn = FORWARD_SLASH.matcher(cn).replaceAll(".");
+                    Class<?> c = classOrNull(cn);
+                    if (c != null && c.isAnnotationPresent(RunWith.class)) {
+                        classes.push(c);
+                    }
+                }
+                jf.close();
+            } catch (IOException e) {
+                System.err.println("Error while reading classes from " + jp);
+            }
+        }
+        return classes.toArray(new Class[classes.size()]);
+    }
+
+    private static Class<?> classOrNull(String className) {
+        try {
+            return Class.forName(className);
+        } catch (ClassNotFoundException e) {
+            System.err.println("Class not found: " + className);
+        } catch (NoClassDefFoundError e) {
+            System.err.println("Class definition not found: " + className);
+        } catch (Exception e) {
+            System.err.println("Other exception while reading class: " + className);
+        }
+        return null;
+    }
+
+    public static void main(String[] args) {
+        JunitTestArgParser parser = JunitTestArgParser.parse(args);
+
+        JUnitCore core = new JUnitCore();
+        GtestLogger logger = new GtestLogger(System.out);
+        core.addListener(new GtestListener(logger));
+        Class[] classes = findClassesFromClasspath();
+        Request testRequest = Request.classes(new GtestComputer(logger), classes);
+        for (String packageFilter : parser.getPackageFilters()) {
+            testRequest = testRequest.filterWith(new PackageFilter(packageFilter));
+        }
+        for (Class<?> runnerFilter : parser.getRunnerFilters()) {
+            testRequest = testRequest.filterWith(new RunnerFilter(runnerFilter));
+        }
+        for (String gtestFilter : parser.getGtestFilters()) {
+            testRequest = testRequest.filterWith(new GtestFilter(gtestFilter));
+        }
+        System.exit(core.run(testRequest).wasSuccessful() ? 0 : 1);
+    }
+
+}
+