[Android] Add gyp support for multidex. (RELAND)

Reland of https://codereview.chromium.org/1278573002

BUG=272790
TBR=thakis@chromium.org,mmenke@chromium.org

Review URL: https://codereview.chromium.org/1318513003

Cr-Commit-Position: refs/heads/master@{#345443}

25 files changed, 459 insertions, 16 deletions

diff --git a/base/BUILD.gn b/base/BUILD.gn
index b6fb63e..a4e5a5c 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -1591,6 +1591,7 @@ if (is_android) {
     ]
 
     deps = [
+      "//third_party/android_tools:android_support_multidex_java",
       "//third_party/jsr-305:jsr_305_javalib",
     ]
 
@@ -1622,12 +1623,29 @@ if (is_android) {
     DEPRECATED_java_in_dir = "test/android/javatests/src"
   }
 
+  # TODO(jbudorick): Remove this once we roll to robolectric 3.0 and pull
+  # in the multidex shadow library. crbug.com/522043
+  # GYP: //base.gyp:base_junit_test_support
+  java_library("base_junit_test_support") {
+    testonly = true
+    java_files = [ "test/android/junit/src/org/chromium/base/test/shadows/ShadowMultiDex.java" ]
+    deps = [
+      "//third_party/android_tools:android_support_multidex_java",
+      "//third_party/robolectric:android-all-4.3_r2-robolectric-0",
+      "//third_party/robolectric:robolectric_java",
+    ]
+  }
+
   # GYP: //base.gyp:base_junit_tests
   junit_binary("base_junit_tests") {
-    java_files = [ "android/junit/src/org/chromium/base/LogTest.java" ]
+    java_files = [
+      "android/junit/src/org/chromium/base/BaseChromiumApplicationTest.java",
+      "android/junit/src/org/chromium/base/LogTest.java",
+    ]
     deps = [
       ":base_java",
       ":base_java_test_support",
+      ":base_junit_test_support",
     ]
   }
 
diff --git a/base/android/java/src/org/chromium/base/BaseChromiumApplication.java b/base/android/java/src/org/chromium/base/BaseChromiumApplication.java
index d7c7b05..6d73c8fe 100644
--- a/base/android/java/src/org/chromium/base/BaseChromiumApplication.java
+++ b/base/android/java/src/org/chromium/base/BaseChromiumApplication.java
@@ -11,6 +11,8 @@ import android.os.Bundle;
 import android.view.KeyEvent;
 import android.view.Window;
 
+import org.chromium.base.multidex.ChromiumMultiDex;
+
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
@@ -20,6 +22,15 @@ import java.lang.reflect.Proxy;
  * Basic application functionality that should be shared among all browser applications.
  */
 public class BaseChromiumApplication extends Application {
+
+    private static final String TAG = "cr.base";
+
+    @Override
+    protected void attachBaseContext(Context base) {
+        super.attachBaseContext(base);
+        ChromiumMultiDex.install(this);
+    }
+
     /**
      * Interface to be implemented by listeners for window focus events.
      */
diff --git a/base/android/java/src/org/chromium/base/annotations/MainDex.java b/base/android/java/src/org/chromium/base/annotations/MainDex.java
new file mode 100644
index 0000000..0b35ade
--- /dev/null
+++ b/base/android/java/src/org/chromium/base/annotations/MainDex.java
@@ -0,0 +1,21 @@
+// Copyright 2015 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.base.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * An annotation that signals that a class should be kept in the main dex file.
+ *
+ * This generally means it's used by renderer processes, which can't load secondary dexes
+ * on K and below.
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.CLASS)
+public @interface MainDex {
+}
diff --git a/base/android/java/src/org/chromium/base/multidex/ChromiumMultiDex.java b/base/android/java/src/org/chromium/base/multidex/ChromiumMultiDex.java
new file mode 100644
index 0000000..2c28673
--- /dev/null
+++ b/base/android/java/src/org/chromium/base/multidex/ChromiumMultiDex.java
@@ -0,0 +1,58 @@
+// Copyright 2015 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.base.multidex;
+
+import android.content.Context;
+import android.os.Build;
+import android.os.Process;
+import android.support.multidex.MultiDex;
+
+import org.chromium.base.Log;
+import org.chromium.base.VisibleForTesting;
+
+import java.lang.reflect.InvocationTargetException;
+
+/**
+ *  Performs multidex installation for non-isolated processes.
+ */
+public class ChromiumMultiDex {
+
+    private static final String TAG = "cr.base.multidex";
+
+    /**
+     *  Installs secondary dexes if possible.
+     *
+     *  Isolated processes (e.g. renderer processes) can't load secondary dex files on
+     *  K and below, so we don't even try in that case.
+     *
+     *  @param context The application context.
+     */
+    @VisibleForTesting
+    public static void install(Context context) {
+        try {
+            // TODO(jbudorick): Back out this version check once support for K & below works.
+            // http://crbug.com/512357
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP && processIsIsolated()) {
+                Log.i(TAG, "Skipping multidex installation: inside isolated process.");
+            } else {
+                MultiDex.install(context);
+                Log.i(TAG, "Completed multidex installation.");
+            }
+        } catch (NoSuchMethodException e) {
+            Log.wtf(TAG, "Failed multidex installation", e);
+        } catch (IllegalAccessException e) {
+            Log.wtf(TAG, "Failed multidex installation", e);
+        } catch (InvocationTargetException e) {
+            Log.wtf(TAG, "Failed multidex installation", e);
+        }
+    }
+
+    // Calls Process.isIsolated, a private Android API.
+    private static boolean processIsIsolated()
+            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
+        return (boolean) Process.class.getMethod("isIsolated").invoke(null);
+    }
+
+}
diff --git a/base/android/junit/src/org/chromium/base/BaseChromiumApplicationTest.java b/base/android/junit/src/org/chromium/base/BaseChromiumApplicationTest.java
index d3441f7..239de67 100644
--- a/base/android/junit/src/org/chromium/base/BaseChromiumApplicationTest.java
+++ b/base/android/junit/src/org/chromium/base/BaseChromiumApplicationTest.java
@@ -13,6 +13,7 @@ import android.view.KeyEvent;
 import junit.framework.Assert;
 
 import org.chromium.base.BaseChromiumApplication.WindowFocusChangedListener;
+import org.chromium.base.test.shadows.ShadowMultiDex;
 import org.chromium.testing.local.LocalRobolectricTestRunner;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -25,10 +26,12 @@ import org.robolectric.util.ActivityController;
 
 /** Unit tests for {@link BaseChromiumApplication}. */
 @RunWith(LocalRobolectricTestRunner.class)
-@Config(manifest = Config.NONE, application = BaseChromiumApplication.class,
-        shadows = {BaseChromiumApplicationTest.TrackingShadowActivity.class})
+@Config(manifest = Config.NONE,
+        application = BaseChromiumApplication.class,
+        shadows = {BaseChromiumApplicationTest.TrackingShadowActivity.class, ShadowMultiDex.class})
 public class BaseChromiumApplicationTest {
 
+    /** Shadow that tracks calls to onWindowFocusChanged and dispatchKeyEvent. */
     @Implements(Activity.class)
     public static class TrackingShadowActivity extends ShadowActivity {
         private int mWindowFocusCalls;
diff --git a/base/base.gyp b/base/base.gyp
index a9038cd..d57ec6e 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -1450,6 +1450,7 @@
             'base_java_library_process_type',
             'base_java_memory_pressure_level',
             'base_native_libraries_gen',
+            '../third_party/android_tools/android_tools.gyp:android_support_multidex_javalib',
             '../third_party/jsr-305/jsr-305.gyp:jsr_305_javalib',
           ],
           'includes': [ '../build/java.gypi' ],
@@ -1507,12 +1508,30 @@
           'includes': [ '../build/java.gypi' ],
         },
         {
+          # TODO(jbudorick): Remove this once we roll to robolectric 3.0 and pull
+          # in the multidex shadow library. crbug.com/522043
+          # GN: //base:base_junit_test_support
+          'target_name': 'base_junit_test_support',
+          'type': 'none',
+          'dependencies': [
+            '../testing/android/junit/junit_test.gyp:junit_test_support',
+            '../third_party/android_tools/android_tools.gyp:android_support_multidex_javalib',
+          ],
+          'variables': {
+            'src_paths': [
+              '../base/test/android/junit/',
+            ],
+          },
+          'includes': [ '../build/host_jar.gypi' ]
+        },
+        {
           # GN: //base:base_junit_tests
           'target_name': 'base_junit_tests',
           'type': 'none',
           'dependencies': [
             'base_java',
             'base_java_test_support',
+            'base_junit_test_support',
             '../testing/android/junit/junit_test.gyp:junit_test_support',
           ],
           'variables': {
diff --git a/base/test/android/javatests/src/org/chromium/base/test/BaseInstrumentationTestRunner.java b/base/test/android/javatests/src/org/chromium/base/test/BaseInstrumentationTestRunner.java
index 35fe9b9..0eab231 100644
--- a/base/test/android/javatests/src/org/chromium/base/test/BaseInstrumentationTestRunner.java
+++ b/base/test/android/javatests/src/org/chromium/base/test/BaseInstrumentationTestRunner.java
@@ -8,6 +8,7 @@ import android.content.Context;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.os.Build;
+import android.os.Bundle;
 import android.test.AndroidTestRunner;
 import android.test.InstrumentationTestRunner;
 import android.text.TextUtils;
@@ -17,6 +18,7 @@ import junit.framework.TestResult;
 
 import org.chromium.base.Log;
 import org.chromium.base.SysUtils;
+import org.chromium.base.multidex.ChromiumMultiDex;
 import org.chromium.base.test.BaseTestResult.SkipCheck;
 import org.chromium.base.test.util.MinAndroidSdkLevel;
 import org.chromium.base.test.util.Restriction;
@@ -32,6 +34,12 @@ public class BaseInstrumentationTestRunner extends InstrumentationTestRunner {
     private static final String TAG = "cr.base.test";
 
     @Override
+    public void onCreate(Bundle arguments) {
+        ChromiumMultiDex.install(getTargetContext());
+        super.onCreate(arguments);
+    }
+
+    @Override
     protected AndroidTestRunner getAndroidTestRunner() {
         AndroidTestRunner runner = new AndroidTestRunner() {
             @Override
diff --git a/base/test/android/junit/src/org/chromium/base/test/shadows/ShadowMultiDex.java b/base/test/android/junit/src/org/chromium/base/test/shadows/ShadowMultiDex.java
new file mode 100644
index 0000000..b3ff57e
--- /dev/null
+++ b/base/test/android/junit/src/org/chromium/base/test/shadows/ShadowMultiDex.java
@@ -0,0 +1,21 @@
+// Copyright 2015 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.base.test.shadows;
+
+import android.content.Context;
+import android.support.multidex.MultiDex;
+
+import org.robolectric.annotation.Implementation;
+import org.robolectric.annotation.Implements;
+
+/** Do-nothing shadow for {@link android.support.multidex.MultiDex}. */
+@Implements(MultiDex.class)
+public class ShadowMultiDex {
+
+    @Implementation
+    public static void install(Context context) {
+    }
+
+}
diff --git a/build/android/ant/apk-package.xml b/build/android/ant/apk-package.xml
index e8b76f7e..cb79560 100644
--- a/build/android/ant/apk-package.xml
+++ b/build/android/ant/apk-package.xml
@@ -54,6 +54,9 @@
   <property name="resource.package.file.name" value="${RESOURCE_PACKAGED_APK_NAME}" />
 
   <property name="intermediate.dex.file" location="${DEX_FILE_PATH}" />
+  <condition property="multidex.enabled" value="true">
+    <equals arg1="${MULTIDEX_ENABLED}" arg2="1"/>
+  </condition>
 
   <!-- Macro that enables passing a variable list of external jar files
        to ApkBuilder. -->
@@ -70,13 +73,32 @@
           hascode="${HAS_CODE}"
           previousBuildType="/"
           buildType="${build.is.packaging.debug}/${build.is.signing.debug}">
-        <dex path="${intermediate.dex.file}"/>
+        <dex path="${intermediate.dex.file}" />
         <nativefolder path="${native.libs.absolute.dir}" />
         <extra-jars/>
       </apkbuilder>
     </sequential>
   </macrodef>
 
+  <macrodef name="multidex-package-helper">
+    <element name="extra-jars" optional="yes" />
+    <sequential>
+      <apkbuilder
+          outfolder="${out.absolute.dir}"
+          resourcefile="${resource.package.file.name}"
+          apkfilepath="${out.packaged.file}"
+          debugpackaging="${build.is.packaging.debug}"
+          debugsigning="${build.is.signing.debug}"
+          verbose="${verbose}"
+          hascode="false"
+          previousBuildType="/"
+          buildType="${build.is.packaging.debug}/${build.is.signing.debug}">
+        <zip path="${intermediate.dex.file}" />
+        <nativefolder path="${native.libs.absolute.dir}" />
+        <extra-jars/>
+      </apkbuilder>
+    </sequential>
+  </macrodef>
 
   <!-- Packages the application. -->
   <target name="-package">
@@ -89,7 +111,14 @@
         </package-helper>
       </then>
       <else>
-        <package-helper />
+        <if condition="${multidex.enabled}">
+          <then>
+            <multidex-package-helper />
+          </then>
+          <else>
+            <package-helper />
+          </else>
+        </if>
       </else>
     </if>
   </target>
diff --git a/build/android/apkbuilder_action.gypi b/build/android/apkbuilder_action.gypi
index 27807d8..e073e9b 100644
--- a/build/android/apkbuilder_action.gypi
+++ b/build/android/apkbuilder_action.gypi
@@ -56,6 +56,11 @@
         '-DDEX_FILE_PATH=<(dex_path)',
       ]
     }],
+    ['enable_multidex == 1', {
+      'action': [
+        '-DMULTIDEX_ENABLED=1',
+      ]
+    }]
   ],
   'action': [
     'python', '<(DEPTH)/build/android/gyp/ant.py',
diff --git a/build/android/gyp/dex.py b/build/android/gyp/dex.py
index c26d23a..3b4141f 100755
--- a/build/android/gyp/dex.py
+++ b/build/android/gyp/dex.py
@@ -4,21 +4,57 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import logging
 import optparse
 import os
 import sys
+import tempfile
+import zipfile
 
 from util import build_utils
 from util import md5_check
 
 
-def DoDex(options, paths):
+def DoMultiDex(options, paths):
+  main_dex_list = []
+  main_dex_list_files = build_utils.ParseGypList(options.main_dex_list_paths)
+  for m in main_dex_list_files:
+    with open(m) as main_dex_list_file:
+      main_dex_list.extend(l for l in main_dex_list_file if l)
+
+  with tempfile.NamedTemporaryFile(suffix='.txt') as combined_main_dex_list:
+    combined_main_dex_list.write('\n'.join(main_dex_list))
+    combined_main_dex_list.flush()
+
+    dex_args = [
+      '--multi-dex',
+      '--minimal-main-dex',
+      '--main-dex-list=%s' % combined_main_dex_list.name
+    ]
+
+    DoDex(options, paths, dex_args=dex_args)
+
+  if options.dex_path.endswith('.zip'):
+    iz = zipfile.ZipFile(options.dex_path, 'r')
+    tmp_dex_path = '%s.tmp.zip' % options.dex_path
+    oz = zipfile.ZipFile(tmp_dex_path, 'w', zipfile.ZIP_DEFLATED)
+    for i in iz.namelist():
+      if i.endswith('.dex'):
+        oz.writestr(i, iz.read(i))
+    os.remove(options.dex_path)
+    os.rename(tmp_dex_path, options.dex_path)
+
+
+def DoDex(options, paths, dex_args=None):
   dx_binary = os.path.join(options.android_sdk_tools, 'dx')
   # See http://crbug.com/272064 for context on --force-jumbo.
   dex_cmd = [dx_binary, '--dex', '--force-jumbo', '--output', options.dex_path]
   if options.no_locals != '0':
     dex_cmd.append('--no-locals')
 
+  if dex_args:
+    dex_cmd += dex_args
+
   dex_cmd += paths
 
   record_path = '%s.md5.stamp' % options.dex_path
@@ -54,9 +90,14 @@ def main():
                           'is enabled.'))
   parser.add_option('--no-locals',
                     help='Exclude locals list from the dex file.')
+  parser.add_option('--multi-dex', default=False, action='store_true',
+                    help='Create multiple dex files.')
   parser.add_option('--inputs', help='A list of additional input paths.')
   parser.add_option('--excluded-paths',
                     help='A list of paths to exclude from the dex file.')
+  parser.add_option('--main-dex-list-paths',
+                    help='A list of paths containing a list of the classes to '
+                         'include in the main dex.')
 
   options, paths = parser.parse_args(args)
 
@@ -76,7 +117,14 @@ def main():
     paths = [p for p in paths if not
              os.path.relpath(p, options.output_directory) in exclude_paths]
 
-  DoDex(options, paths)
+  if options.multi_dex and options.main_dex_list_paths:
+    DoMultiDex(options, paths)
+  else:
+    if options.multi_dex:
+      logging.warning('--multi-dex is unused without --main-dex-list-paths')
+    elif options.main_dex_list_paths:
+      logging.warning('--main-dex-list-paths is unused without --multi-dex')
+    DoDex(options, paths)
 
   if options.depfile:
     build_utils.WriteDepfile(
diff --git a/build/android/gyp/main_dex_list.py b/build/android/gyp/main_dex_list.py
new file mode 100755
index 0000000..6442001
--- /dev/null
+++ b/build/android/gyp/main_dex_list.py
@@ -0,0 +1,84 @@
+#!/usr/bin/env python
+#
+# Copyright 2015 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.
+
+import argparse
+import os
+import sys
+import tempfile
+
+from util import build_utils
+
+sys.path.append(os.path.abspath(os.path.join(
+    os.path.dirname(__file__), os.pardir)))
+from pylib import constants
+
+
+def main():
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--android-sdk-tools', required=True,
+                      help='Android sdk build tools directory.')
+  parser.add_argument('--main-dex-rules-path', action='append', default=[],
+                      dest='main_dex_rules_paths',
+                      help='A file containing a list of proguard rules to use '
+                           'in determining the class to include in the '
+                           'main dex.')
+  parser.add_argument('--main-dex-list-path', required=True,
+                      help='The main dex list file to generate.')
+  parser.add_argument('paths', nargs='+',
+                      help='JARs for which a main dex list should be '
+                           'generated.')
+
+  args = parser.parse_args()
+
+  with open(args.main_dex_list_path, 'w') as main_dex_list_file:
+
+    shrinked_android_jar = os.path.abspath(
+        os.path.join(args.android_sdk_tools, 'lib', 'shrinkedAndroid.jar'))
+    dx_jar = os.path.abspath(
+        os.path.join(args.android_sdk_tools, 'lib', 'dx.jar'))
+    paths_arg = ':'.join(args.paths)
+    rules_file = os.path.abspath(
+        os.path.join(args.android_sdk_tools, 'mainDexClasses.rules'))
+
+    with tempfile.NamedTemporaryFile(suffix='.jar') as temp_jar:
+      proguard_cmd = [
+        constants.PROGUARD_SCRIPT_PATH,
+        '-forceprocessing',
+        '-dontwarn', '-dontoptimize', '-dontobfuscate', '-dontpreverify',
+        '-injars', paths_arg,
+        '-outjars', temp_jar.name,
+        '-libraryjars', shrinked_android_jar,
+        '-include', rules_file,
+      ]
+      for m in args.main_dex_rules_paths:
+        proguard_cmd.extend(['-include', m])
+
+      main_dex_list = ''
+      try:
+        build_utils.CheckOutput(proguard_cmd)
+
+        java_cmd = [
+          'java', '-cp', dx_jar,
+          'com.android.multidex.MainDexListBuilder',
+          temp_jar.name, paths_arg
+        ]
+        main_dex_list = build_utils.CheckOutput(java_cmd)
+      except build_utils.CalledProcessError as e:
+        if 'output jar is empty' in e.output:
+          pass
+        elif "input doesn't contain any classes" in e.output:
+          pass
+        else:
+          raise
+
+      main_dex_list_file.write(main_dex_list)
+
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())
+
diff --git a/build/android/main_dex_action.gypi b/build/android/main_dex_action.gypi
new file mode 100644
index 0000000..06717dd
--- /dev/null
+++ b/build/android/main_dex_action.gypi
@@ -0,0 +1,44 @@
+# Copyright 2015 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.
+
+# This file is meant to be included into an action to provide a rule that
+# generates a list of classes that must be kept in the main dex file.
+#
+# To use this, create a gyp target with the following form:
+#  {
+#    'action_name': 'some name for the action'
+#    'actions': [
+#      'variables': {
+#        'jar_path': 'path to jar',
+#        'output_path': 'output path'
+#      },
+#      'includes': [ 'relative/path/to/main_dex_action.gypi' ],
+#    ],
+#  },
+#
+
+{
+  'message': 'Generating main dex classes list for <(jar_path)',
+  'variables': {
+    'jar_path%': '',
+    'output_path%': '',
+    'main_dex_list_script': '<(DEPTH)/build/android/gyp/main_dex_list.py',
+    'main_dex_rules_path': '<(DEPTH)/build/android/main_dex_classes.flags',
+  },
+  'inputs': [
+    '<(jar_path)',
+    '<(main_dex_list_script)',
+    '<(main_dex_rules_path)',
+  ],
+  'outputs': [
+    '<(output_path)',
+  ],
+  'action': [
+    'python', '<(main_dex_list_script)',
+    '--main-dex-list-path', '<(output_path)',
+    '--android-sdk-tools', '<(android_sdk_tools)',
+    '--main-dex-rules-path', '<(main_dex_rules_path)',
+    '<(jar_path)',
+  ]
+}
diff --git a/build/android/main_dex_classes.flags b/build/android/main_dex_classes.flags
new file mode 100644
index 0000000..d9689b2
--- /dev/null
+++ b/build/android/main_dex_classes.flags
@@ -0,0 +1,3 @@
+-keep @**.MainDex class * {
+  *;
+}
diff --git a/build/android/pylib/constants/__init__.py b/build/android/pylib/constants/__init__.py
index 4617119..43c0a6d 100644
--- a/build/android/pylib/constants/__init__.py
+++ b/build/android/pylib/constants/__init__.py
@@ -189,6 +189,9 @@ ANDROID_SDK_TOOLS = os.path.join(ANDROID_SDK_ROOT,
 ANDROID_NDK_ROOT = os.path.join(DIR_SOURCE_ROOT,
                                 'third_party/android_tools/ndk')
 
+PROGUARD_SCRIPT_PATH = os.path.join(
+    ANDROID_SDK_ROOT, 'tools', 'proguard', 'bin', 'proguard.sh')
+
 EMULATOR_SDK_ROOT = os.environ.get('ANDROID_EMULATOR_SDK_ROOT',
                                    os.path.join(DIR_SOURCE_ROOT,
                                                 'android_emulator_sdk'))
diff --git a/build/config/android/rules.gni b/build/config/android/rules.gni
index 3f14b6762..88276bf 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -940,6 +940,9 @@ template("java_library") {
 #   proguard_preprocess: If true, proguard preprocessing will be run. This can
 #     be used to remove unwanted parts of the library.
 #   proguard_config: Path to the proguard config for preprocessing.
+#   supports_android: If true, Android targets (android_library, android_apk)
+#     may depend on this target. Note: if true, this target must only use the
+#     subset of Java available on Android.
 #
 # Example
 #   java_prebuilt("foo_java") {
diff --git a/build/java.gypi b/build/java.gypi
index 614d50a..dc642b9 100644
--- a/build/java.gypi
+++ b/build/java.gypi
@@ -64,6 +64,7 @@
     'instr_stamp': '<(intermediate_dir)/instr.stamp',
     'additional_input_paths': [],
     'dex_path': '<(PRODUCT_DIR)/lib.java/<(_target_name).dex.jar',
+    'main_dex_list_path': '<(intermediate_dir)/main_dex_list.txt',
     'generated_src_dirs': ['>@(generated_R_dirs)'],
     'generated_R_dirs': [],
     'has_java_resources%': 0,
@@ -113,6 +114,7 @@
         'variables': {
           'input_jars_paths': ['<(jar_final_path)'],
           'library_dexed_jars_paths': ['<(dex_path)'],
+          'main_dex_list_paths': ['<(main_dex_list_path)'],
         },
       },
     }],
@@ -309,6 +311,14 @@
       ]
     },
     {
+      'action_name': 'main_dex_list_for_<(_target_name)',
+      'variables': {
+        'jar_path': '<(javac_jar_path)',
+        'output_path': '<(main_dex_list_path)',
+      },
+      'includes': [ 'android/main_dex_action.gypi' ],
+    },
+    {
       'action_name': 'instr_jar_<(_target_name)',
       'message': 'Instrumenting <(_target_name) jar',
       'variables': {
diff --git a/build/java_apk.gypi b/build/java_apk.gypi
index 6dbb858..52902a0 100644
--- a/build/java_apk.gypi
+++ b/build/java_apk.gypi
@@ -70,11 +70,14 @@
   'variables': {
     'tested_apk_obfuscated_jar_path%': '/',
     'tested_apk_dex_path%': '/',
+    'tested_apk_is_multidex%': 0,
     'additional_input_paths': [],
     'create_density_splits%': 0,
     'language_splits': [],
     'input_jars_paths': [],
     'library_dexed_jars_paths': [],
+    'main_dex_list_path': '<(intermediate_dir)/main_dex_list.txt',
+    'main_dex_list_paths': ['<(main_dex_list_path)'],
     'additional_src_dirs': [],
     'generated_src_dirs': [],
     'app_manifest_version_name%': '<(android_app_version_name)',
@@ -131,7 +134,7 @@
     'jar_path': '<(PRODUCT_DIR)/lib.java/<(jar_name)',
     'obfuscated_jar_path': '<(intermediate_dir)/obfuscated.jar',
     'test_jar_path': '<(PRODUCT_DIR)/test.lib.java/<(apk_name).jar',
-    'dex_path': '<(intermediate_dir)/classes.dex',
+    'enable_multidex%': 0,
     'emma_device_jar': '<(android_sdk_root)/tools/lib/emma_device.jar',
     'android_manifest_path%': '<(java_in_dir)/AndroidManifest.xml',
     'split_android_manifest_path': '<(intermediate_dir)/split-manifests/<(android_app_abi)/AndroidManifest.xml',
@@ -160,6 +163,7 @@
         'unsigned_apk_path': '<(intermediate_dir)/<(apk_name)-unsigned.apk',
         'unsigned_abi_split_apk_path': '<(intermediate_dir)/<(apk_name)-abi-<(android_app_abi)-unsigned.apk',
         'create_abi_split%': 0,
+        'enable_multidex%': 0,
       },
       'unsigned_apk_path': '<(unsigned_apk_path)',
       'unsigned_abi_split_apk_path': '<(unsigned_abi_split_apk_path)',
@@ -193,6 +197,11 @@
         }, {
           'managed_input_apk_path': '<(unsigned_apk_path)',
         }],
+        ['enable_multidex == 1', {
+          'dex_path': '<(intermediate_dir)/classes.dex.zip',
+        }, {
+          'dex_path': '<(intermediate_dir)/classes.dex',
+        }],
       ],
     },
     'native_lib_target%': '',
@@ -213,6 +222,7 @@
     'native_lib_placeholder_stamp': '<(apk_package_native_libs_dir)/<(android_app_abi)/native_lib_placeholder.stamp',
     'native_lib_placeholders': [],
     'main_apk_name': '<(apk_name)',
+    'dex_path': '<(dex_path)',
     'enable_errorprone%': '0',
     'errorprone_exe_path': '<(PRODUCT_DIR)/bin.java/chromium_errorprone',
   },
@@ -231,6 +241,7 @@
       'apk_output_jar_path': '<(jar_path)',
       'tested_apk_obfuscated_jar_path': '<(obfuscated_jar_path)',
       'tested_apk_dex_path': '<(dex_path)',
+      'tested_apk_is_multidex': '<(enable_multidex)',
     },
   },
   'conditions': [
@@ -752,8 +763,7 @@
           ],
         },
       ],
-    },
-    ]
+    }],
   ],
   'dependencies': [
     '<(DEPTH)/tools/android/md5sum/md5sum.gyp:md5sum',
@@ -885,6 +895,14 @@
       ],
     },
     {
+      'action_name': 'main_dex_list_for_<(_target_name)',
+      'variables': {
+        'jar_path': '<(javac_jar_path)',
+        'output_path': '<(main_dex_list_path)',
+      },
+      'includes': [ 'android/main_dex_action.gypi' ],
+    },
+    {
       'action_name': 'instr_jar_<(_target_name)',
       'message': 'Instrumenting <(_target_name) jar',
       'variables': {
@@ -1005,14 +1023,40 @@
     {
       'action_name': 'dex_<(_target_name)',
       'variables': {
+        'dex_additional_options': [],
         'dex_input_paths': [
-          '>@(library_dexed_jars_paths)',
           '<(jar_path)',
         ],
         'output_path': '<(dex_path)',
         'proguard_enabled_input_path': '<(obfuscated_jar_path)',
       },
+      'conditions': [
+        ['enable_multidex == 1', {
+          'variables': {
+            'dex_additional_options': [
+              '--multi-dex',
+              '--main-dex-list-paths', '>@(main_dex_list_paths)',
+            ],
+          },
+          'inputs': [
+            '>@(main_dex_list_paths)',
+          ],
+        }]
+      ],
       'target_conditions': [
+        ['enable_multidex == 1 or tested_apk_is_multidex == 1', {
+          'variables': {
+            'dex_input_paths': [
+              '>@(input_jars_paths)',
+            ],
+          },
+        }, {
+          'variables': {
+            'dex_input_paths': [
+              '>@(library_dexed_jars_paths)',
+            ],
+          },
+        }],
         ['emma_instrument != 0', {
           'variables': {
             'dex_no_locals': 1,
diff --git a/build/secondary/third_party/android_tools/BUILD.gn b/build/secondary/third_party/android_tools/BUILD.gn
index a6b3758..175409b 100644
--- a/build/secondary/third_party/android_tools/BUILD.gn
+++ b/build/secondary/third_party/android_tools/BUILD.gn
@@ -49,6 +49,11 @@ android_java_prebuilt("android_support_design_java") {
   jar_path = "$android_sdk_root/extras/android/support/design/libs/android-support-design.jar"
 }
 
+java_prebuilt("android_support_multidex_java") {
+  supports_android = true
+  jar_path = "$android_sdk_root/extras/android/support/multidex/library/libs/android-support-multidex.jar"
+}
+
 android_java_prebuilt("android_support_v13_java") {
   jar_path =
       "$android_sdk_root/extras/android/support/v13/android-support-v13.jar"
diff --git a/chrome/android/BUILD.gn b/chrome/android/BUILD.gn
index 67e7710..49e3598 100644
--- a/chrome/android/BUILD.gn
+++ b/chrome/android/BUILD.gn
@@ -474,6 +474,7 @@ junit_binary("chrome_junit_tests") {
     ":chrome_java",
     "//base:base_java",
     "//base:base_java_test_support",
+    "//base:base_junit_test_support",
     "//sync:sync_java_test_support",
     "//sync/android:sync_java",
     "//third_party/junit:hamcrest",
diff --git a/chrome/android/junit/src/org/chromium/chrome/browser/media/remote/AbstractMediaRouteControllerTest.java b/chrome/android/junit/src/org/chromium/chrome/browser/media/remote/AbstractMediaRouteControllerTest.java
index 54522d8..d8809d2 100644
--- a/chrome/android/junit/src/org/chromium/chrome/browser/media/remote/AbstractMediaRouteControllerTest.java
+++ b/chrome/android/junit/src/org/chromium/chrome/browser/media/remote/AbstractMediaRouteControllerTest.java
@@ -32,6 +32,7 @@ import android.support.v7.media.MediaRouter.RouteInfo;
 import org.chromium.base.ApplicationStatus;
 import org.chromium.base.BaseChromiumApplication;
 import org.chromium.base.CommandLine;
+import org.chromium.base.test.shadows.ShadowMultiDex;
 import org.chromium.base.test.util.Feature;
 import org.chromium.chrome.browser.media.remote.MediaRouteController.MediaStateListener;
 import org.chromium.chrome.browser.media.remote.MediaRouteController.UiListener;
@@ -51,8 +52,8 @@ import org.robolectric.internal.ReflectionHelpers;
 
 /** Tests for {@link AbstractMediaRouteController}. */
 @RunWith(LocalRobolectricTestRunner.class)
-@Config(manifest = Config.NONE, shadows = AbstractMediaRouteControllerTest.ShadowMediaRouter.class,
-        application = BaseChromiumApplication.class)
+@Config(manifest = Config.NONE, application = BaseChromiumApplication.class,
+        shadows = {AbstractMediaRouteControllerTest.ShadowMediaRouter.class, ShadowMultiDex.class})
 public class AbstractMediaRouteControllerTest {
 
     /** Reset the environment before each test. */
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index 9348234..68ed2e1 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -3045,6 +3045,7 @@
             'chrome_java',
             '../base/base.gyp:base',
             '../base/base.gyp:base_java_test_support',
+            '../base/base.gyp:base_junit_test_support',
             '../sync/sync.gyp:sync_java_test_support',
             '../testing/android/junit/junit_test.gyp:junit_test_support',
           ],
diff --git a/net/android/BUILD.gn b/net/android/BUILD.gn
index 86b9c86..c891da7 100644
--- a/net/android/BUILD.gn
+++ b/net/android/BUILD.gn
@@ -87,6 +87,7 @@ junit_binary("net_junit_tests") {
     ":net_java",
     "//base:base_java",
     "//base:base_java_test_support",
+    "//base:base_junit_test_support",
     "//third_party/junit:hamcrest",
   ]
 }
diff --git a/net/android/junit/src/org/chromium/net/HttpNegotiateAuthenticatorTest.java b/net/android/junit/src/org/chromium/net/HttpNegotiateAuthenticatorTest.java
index f6a97c0..7edc4e3 100644
--- a/net/android/junit/src/org/chromium/net/HttpNegotiateAuthenticatorTest.java
+++ b/net/android/junit/src/org/chromium/net/HttpNegotiateAuthenticatorTest.java
@@ -29,6 +29,7 @@ import android.os.Bundle;
 import android.os.Handler;
 
 import org.chromium.base.BaseChromiumApplication;
+import org.chromium.base.test.shadows.ShadowMultiDex;
 import org.chromium.testing.local.LocalRobolectricTestRunner;
 import org.junit.Before;
 import org.junit.Test;
@@ -45,9 +46,9 @@ import java.io.IOException;
  * Robolectric tests for HttpNegotiateAuthenticator
  */
 @RunWith(LocalRobolectricTestRunner.class)
-@Config(manifest = Config.NONE,
-        shadows = HttpNegotiateAuthenticatorTest.ExtendedShadowAccountManager.class,
-        application = BaseChromiumApplication.class)
+@Config(manifest = Config.NONE, application = BaseChromiumApplication.class,
+        shadows = {HttpNegotiateAuthenticatorTest.ExtendedShadowAccountManager.class,
+                ShadowMultiDex.class})
 public class HttpNegotiateAuthenticatorTest {
     // Since the account manager is an SDK singleton (it is fetched using AccountManager.get()) we
     // can't validate its method calls with Mockito, so do so using our shadow method. Since the
diff --git a/net/net.gyp b/net/net.gyp
index 66d8ae3..d4fe51b 100644
--- a/net/net.gyp
+++ b/net/net.gyp
@@ -1545,6 +1545,7 @@
             'net_java',
             '../base/base.gyp:base',
             '../base/base.gyp:base_java_test_support',
+            '../base/base.gyp:base_junit_test_support',
             '../testing/android/junit/junit_test.gyp:junit_test_support',
           ],
           'variables': {