(Reland) Expose resources in Robolectric/JUnit tests.

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

 // Copyright 2017 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.robolectric.annotation.Config;
 import org.robolectric.internal.ManifestFactory;
 import org.robolectric.internal.ManifestIdentifier;
 import org.robolectric.manifest.AndroidManifest;
+import org.robolectric.res.Fs;
+import org.robolectric.res.FsFile;
+import org.robolectric.res.ResourcePath;
 
-// TODO(mikecase): Add support for specifying the AndroidManifest for
-// Robolectric tests.
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Class that manages passing Android manifest information to Robolectric.
  */
 public class GNManifestFactory implements ManifestFactory {
-    private static final String DEFAULT_PACKAGE_NAME = "org.robolectric.default";
+    private static final String CHROMIUM_MANIFEST_PATH = "chromium.robolectric.manifest";
+    private static final String CHROMIUM_RES_DIRECTORIES = "chromium.robolectric.resource.dirs";
 
     @Override
     public ManifestIdentifier identify(Config config) {
-        if (!config.manifest().equals(Config.NONE)) {
-            throw new RuntimeException("Specifying custom manifest not currently supported. "
-                    + "Please use annotation @Config(manifest = Config.NONE) on Robolectric tests "
-                    + "for the time being.");
+        if (config.resourceDir() != null
+                && !config.resourceDir().equals(Config.DEFAULT_RES_FOLDER)) {
+            throw new RuntimeException("Resource dirs should be generated automatically by GN. "
+                    + "Make sure you specify the correct app package_name in the GN build file. "
+                    + "Make sure you run the tests using the generated run_<test name> scripts.");
         }
+
+        if (config.manifest() != null && !config.manifest().equals(Config.NONE)) {
+            throw new RuntimeException("Specify manifest path in GN build file.");
+        }
+
         return new ManifestIdentifier(null, null, null, config.packageName(), null);
     }
 
     @Override
     public AndroidManifest create(ManifestIdentifier manifestIdentifier) {
-        String packageName = manifestIdentifier.getPackageName();
-        if (packageName == null || packageName.equals("")) {
-            packageName = DEFAULT_PACKAGE_NAME;
+        String manifestPath = System.getProperty(CHROMIUM_MANIFEST_PATH);
+        String resourceDirs = System.getProperty(CHROMIUM_RES_DIRECTORIES);
+
+        final List<FsFile> resourceDirsList = new ArrayList<FsFile>();
+        if (resourceDirs != null) {
+            for (String resourceDir : resourceDirs.split(":")) {
+                resourceDirsList.add(Fs.fileFromPath(resourceDir));
+            }
         }
 
-        return new AndroidManifest(null, null, null, packageName);
+        FsFile manifestFile = null;
+        if (manifestPath != null) {
+            manifestFile = Fs.fileFromPath(manifestPath);
+        }
+
+        return new AndroidManifest(manifestFile, null, null, manifestIdentifier.getPackageName()) {
+            @Override
+            public List<ResourcePath> getIncludedResourcePaths() {
+                List<ResourcePath> paths = super.getIncludedResourcePaths();
+                for (FsFile resourceDir : resourceDirsList) {
+                    paths.add(new ResourcePath(getRClass(), resourceDir, getAssetsDirectory()));
+                }
+                return paths;
+            }
+        };
     }
 }