[Android] Add gn support for multidex.

BUG=272790

Review URL: https://codereview.chromium.org/1451483002

Cr-Commit-Position: refs/heads/master@{#360943}

2 files changed, 72 insertions, 3 deletions

diff --git a/build/config/android/internal_rules.gni b/build/config/android/internal_rules.gni
index f676010..3d91676 100644
--- a/build/config/android/internal_rules.gni
+++ b/build/config/android/internal_rules.gni
@@ -223,6 +223,51 @@ template("java_binary_script") {
 template("dex") {
   set_sources_assignment_filter([])
 
+  _enable_multidex = defined(invoker.enable_multidex) && invoker.enable_multidex
+
+  if (_enable_multidex) {
+    _main_dex_list_path = invoker.output + ".main_dex_list"
+    _main_dex_list_target_name = "${target_name}__main_dex_list"
+    action(_main_dex_list_target_name) {
+      forward_variables_from(invoker,
+                             [
+                               "deps",
+                               "inputs",
+                               "sources",
+                               "testonly",
+                             ])
+
+      script = "//build/android/gyp/main_dex_list.py"
+      depfile = "$target_gen_dir/$target_name.d"
+
+      main_dex_rules = "//build/android/main_dex_classes.flags"
+
+      outputs = [
+        depfile,
+        _main_dex_list_path,
+      ]
+
+      args = [
+        "--depfile",
+        rebase_path(depfile, root_build_dir),
+        "--android-sdk-tools",
+        rebased_android_sdk_build_tools,
+        "--main-dex-list-path",
+        rebase_path(_main_dex_list_path, root_build_dir),
+        "--main-dex-rules-path",
+        rebase_path(main_dex_rules, root_build_dir),
+      ]
+
+      if (defined(invoker.args)) {
+        args += invoker.args
+      }
+
+      if (defined(invoker.sources)) {
+        args += rebase_path(invoker.sources, root_build_dir)
+      }
+    }
+  }
+
   assert(defined(invoker.output))
   action(target_name) {
     forward_variables_from(invoker,
@@ -258,6 +303,16 @@ template("dex") {
       args += [ "--no-locals=1" ]
     }
 
+    if (_enable_multidex) {
+      args += [
+        "--multi-dex",
+        "--main-dex-list-path",
+        rebase_path(_main_dex_list_path, root_build_dir),
+      ]
+      deps += [ ":${_main_dex_list_target_name}" ]
+      inputs += [ _main_dex_list_path ]
+    }
+
     if (defined(invoker.args)) {
       args += invoker.args
     }
diff --git a/build/config/android/rules.gni b/build/config/android/rules.gni
index 95e1303..e656070 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -1240,7 +1240,12 @@ template("android_apk") {
   _rebased_lib_dex_path = rebase_path(_lib_dex_path, root_build_dir)
   _template_name = target_name
 
-  final_dex_path = "$gen_dir/classes.dex"
+  enable_multidex = defined(invoker.enable_multidex) && invoker.enable_multidex
+  if (enable_multidex) {
+    final_dex_path = "$gen_dir/classes.dex.zip"
+  } else {
+    final_dex_path = "$gen_dir/classes.dex"
+  }
   final_dex_target_name = "${_template_name}__final_dex"
 
   _final_apk_path = ""
@@ -1552,18 +1557,27 @@ template("android_apk") {
     _dex_sources = [ _proguard_jar_path ]
     _dex_deps = [ ":$_proguard_target" ]
   } else {
-    _dex_sources = [ _lib_dex_path ]
+    if (enable_multidex) {
+      _dex_sources = [ _jar_path ]
+    } else {
+      _dex_sources = [ _lib_dex_path ]
+    }
     _dex_deps = [ ":$java_target" ]
   }
 
   dex("$final_dex_target_name") {
+    forward_variables_from(invoker, [ "enable_multidex" ])
     deps = _dex_deps + [ ":$build_config_target" ]
     inputs = [
       _build_config,
     ]
     sources = _dex_sources
     output = final_dex_path
-    _dex_arg_key = "${_rebased_build_config}:final_dex:dependency_dex_files"
+    if (enable_multidex) {
+      _dex_arg_key = "${_rebased_build_config}:dist_jar:dependency_jars"
+    } else {
+      _dex_arg_key = "${_rebased_build_config}:final_dex:dependency_dex_files"
+    }
     args = [ "--inputs=@FileArg($_dex_arg_key)" ]
 
     if (emma_coverage && !_emma_never_instrument) {