Android: Make incremental install work for two <instrumentation>

This happens in the case of junit4

Review-Url: https://codereview.chromium.org/2790453003
Cr-Original-Commit-Position: refs/heads/master@{#460839}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 4e5061771986fd0d506d21f33a0d8fdb065add92

android/incremental_install/BUILD.gn

@@ -13,6 +13,7 @@ android_library("bootstrap_java") {
     "java/org/chromium/incrementalinstall/ClassLoaderPatcher.java",
     "java/org/chromium/incrementalinstall/LockFile.java",
     "java/org/chromium/incrementalinstall/Reflect.java",
+    "java/org/chromium/incrementalinstall/SecondInstrumentation.java",
   ]
   emma_never_instrument = true
   run_findbugs_override = false

android/incremental_install/generate_android_manifest.py

@@ -22,9 +22,15 @@ ElementTree.register_namespace('android', _ANDROID_NAMESPACE)
 
 _INCREMENTAL_APP_NAME = 'org.chromium.incrementalinstall.BootstrapApplication'
 _META_DATA_APP_NAME = 'incremental-install-real-app'
-_META_DATA_INSTRUMENTATION_NAME = 'incremental-install-real-instrumentation'
 _DEFAULT_APPLICATION_CLASS = 'android.app.Application'
-_DEFAULT_INSTRUMENTATION_CLASS = 'android.app.Instrumentation'
+_META_DATA_INSTRUMENTATION_NAMES = [
+    'incremental-install-real-instrumentation-0',
+    'incremental-install-real-instrumentation-1',
+]
+_INCREMENTAL_INSTRUMENTATION_CLASSES = [
+    'android.app.Instrumentation',
+    'org.chromium.incrementalinstall.SecondInstrumentation',
+]
 
 
 def _AddNamespace(name):
@@ -84,12 +90,13 @@ def _ProcessManifest(main_manifest, disable_isolated_processes):
 
   # Seems to be a bug in ElementTree, as doc.find() doesn't work here.
   instrumentation_nodes = doc.findall('instrumentation')
-  if instrumentation_nodes:
-    instrumentation_node = instrumentation_nodes[0]
+  assert len(instrumentation_nodes) <= 2, (
+      'Need to update incremental install to support >2 <instrumentation> tags')
+  for i, instrumentation_node in enumerate(instrumentation_nodes):
     real_instrumentation_class = instrumentation_node.get(_AddNamespace('name'))
     instrumentation_node.set(_AddNamespace('name'),
-                             _DEFAULT_INSTRUMENTATION_CLASS)
-    _CreateMetaData(app_node, _META_DATA_INSTRUMENTATION_NAME,
+                             _INCREMENTAL_INSTRUMENTATION_CLASSES[i])
+    _CreateMetaData(app_node, _META_DATA_INSTRUMENTATION_NAMES[i],
                     real_instrumentation_class)
 
   return ElementTree.tostring(doc, encoding='UTF-8')

android/incremental_install/java/org/chromium/incrementalinstall/BootstrapApplication.java

@@ -32,8 +32,10 @@ public final class BootstrapApplication extends Application {
     private static final String TAG = "cr.incrementalinstall";
     private static final String MANAGED_DIR_PREFIX = "/data/local/tmp/incremental-app-";
     private static final String REAL_APP_META_DATA_NAME = "incremental-install-real-app";
-    private static final String REAL_INSTRUMENTATION_META_DATA_NAME =
-            "incremental-install-real-instrumentation";
+    private static final String REAL_INSTRUMENTATION_META_DATA_NAME0 =
+            "incremental-install-real-instrumentation-0";
+    private static final String REAL_INSTRUMENTATION_META_DATA_NAME1 =
+            "incremental-install-real-instrumentation-1";
 
     private ClassLoaderPatcher mClassLoaderPatcher;
     private Application mRealApplication;
@@ -113,9 +115,11 @@ public final class BootstrapApplication extends Application {
             // mInstrumentationAppDir is one of a set of fields that is initialized only when
             // instrumentation is active.
             if (Reflect.getField(mActivityThread, "mInstrumentationAppDir") != null) {
-                String realInstrumentationName =
-                        getClassNameFromMetadata(REAL_INSTRUMENTATION_META_DATA_NAME, instContext);
-                initInstrumentation(realInstrumentationName);
+                String metaDataName = REAL_INSTRUMENTATION_META_DATA_NAME0;
+                if (mOrigInstrumentation instanceof SecondInstrumentation) {
+                    metaDataName = REAL_INSTRUMENTATION_META_DATA_NAME1;
+                }
+                initInstrumentation(getClassNameFromMetadata(metaDataName, instContext));
             } else {
                 Log.i(TAG, "No instrumentation active.");
             }

android/incremental_install/java/org/chromium/incrementalinstall/SecondInstrumentation.java

@@ -0,0 +1,12 @@
+// 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.incrementalinstall;
+
+import android.app.Instrumentation;
+
+/**
+ * Exists to support an app having multiple instrumentations.
+ */
+public final class SecondInstrumentation extends Instrumentation {}