Android: Using R8 instead of ProGuard for public targets

Bug: 908988
Change-Id: Iaaee8124c56945a8769e6d4ff2a0859ef39c1aea
Reviewed-on: https://chromium-review.googlesource.com/c/1355424Reviewed-by: agrieve <agrieve@chromium.org>
Commit-Queue: Sam Maier <smaier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612439}

build/config/android/config.gni

@@ -216,8 +216,12 @@ if (is_android || is_chromeos) {
         "//third_party/android_build_tools/aapt2/aapt2"
 
     # Use r8 for Java optimization rather than ProGuard.
-    # This will evenutally be the default. https://crbug.com/872904
-    experimental_use_r8 = false
+    # This will evenutally be the default. https://crbug.com/908988
+    # -1 will turn it on only for public targets, 0 turns it off for all, and 1
+    # turns it on for all targets.
+    # TODO(smaier): Once R8 is acceptable for all usages, make this a bool and
+    # get rid of the use_r8 variable everywhere.
+    experimental_use_r8 = -1
   }
 
   # We need a second declare_args block to make sure we are using the overridden

build/config/android/internal_rules.gni

@@ -940,6 +940,9 @@ if (enable_java_templates) {
                              ])
       script = "//build/android/gyp/proguard.py"
 
+      _use_r8 = (defined(invoker.use_r8) && invoker.use_r8) ||
+                experimental_use_r8 == 1
+
       # http://crbug.com/725224. Fix for bots running out of memory.
       pool = "//build/toolchain:link_pool($default_toolchain)"
 
@@ -980,7 +983,7 @@ if (enable_java_templates) {
         "--classpath",
         "@FileArg($_rebased_build_config:android:sdk_jars)",
       ]
-      if (experimental_use_r8) {
+      if (_use_r8) {
         args += [
           "--r8-path",
           rebase_path(_r8_path, root_build_dir),
@@ -1067,7 +1070,9 @@ if (enable_java_templates) {
 
     _proguard_enabled =
         defined(invoker.proguard_enabled) && invoker.proguard_enabled
-    _proguarding_with_r8 = _proguard_enabled && experimental_use_r8
+    _use_r8 =
+        (defined(invoker.use_r8) && invoker.use_r8) || experimental_use_r8 == 1
+    _proguarding_with_r8 = _use_r8 && _proguard_enabled
 
     assert(!(defined(invoker.input_jars) && _proguard_enabled),
            "input_jars can't be specified when proguarding a dex.")
@@ -1107,6 +1112,7 @@ if (enable_java_templates) {
                                  "proguard_mapping_path",
                                  "testonly",
                                ])
+        use_r8 = _use_r8
         inputs = []
         if (defined(invoker.inputs)) {
           inputs += invoker.inputs
@@ -3373,6 +3379,7 @@ if (enable_java_templates) {
 
         if (defined(_dex_path)) {
           dex("${target_name}__dex") {
+            forward_variables_from(invoker, [ "use_r8" ])
             input_jars = [ _final_jar_path ]
             output = _dex_path
             deps = [

build/config/android/rules.gni

@@ -1598,7 +1598,11 @@ if (enable_java_templates) {
       deps = _deps
       build_config = _build_config
       proguard_enabled = true
-      forward_variables_from(invoker, [ "proguard_configs" ])
+      forward_variables_from(invoker,
+                             [
+                               "proguard_configs",
+                               "use_r8",
+                             ])
       output = invoker.output
     }
   }
@@ -2451,6 +2455,7 @@ if (enable_java_templates) {
                                "javac_args",
                                "loadable_modules",
                                "no_build_hooks",
+                               "use_r8",
                                "secondary_abi_loadable_modules",
                              ])
       if (_is_bundle_module) {
@@ -2539,6 +2544,7 @@ if (enable_java_templates) {
         forward_variables_from(invoker,
                                [
                                  "min_sdk_version",
+                                 "use_r8",
                                  "dexlayout_profile",
                                ])
         proguard_enabled = _proguard_enabled
@@ -2970,6 +2976,7 @@ if (enable_java_templates) {
                                "uncompress_shared_libraries",
                                "uncompress_dex",
                                "use_chromium_linker",
+                               "use_r8",
                                "version_code",
                                "version_name",
                                "write_asset_list",
@@ -3072,6 +3079,7 @@ if (enable_java_templates) {
                                "testonly",
                                "uncompress_shared_libraries",
                                "use_chromium_linker",
+                               "use_r8",
                                "version_code",
                                "version_name",
                                "write_asset_list",
@@ -3888,7 +3896,11 @@ if (enable_java_templates) {
         enable_multidex = _enable_multidex
         proguard_enabled = true
         proguard_mapping_path = _proguard_mapping_path
-        forward_variables_from(invoker, [ "proguard_jar_path" ])
+        forward_variables_from(invoker,
+                               [
+                                 "proguard_jar_path",
+                                 "use_r8",
+                               ])
         build_config = _build_config
 
         deps = _module_targets + _module_build_config_targets +

chrome/android/BUILD.gn

@@ -1486,8 +1486,10 @@ template("chrome_public_apk_or_module_tmpl") {
     load_library_from_apk = _is_modern && chromium_linker_supported
 
     version_name = chrome_version_name
-    if (!experimental_use_r8) {
+    if (experimental_use_r8 == 0) {
       enable_multidex = true
+    } else {
+      use_r8 = true
     }
   }
 }
@@ -1582,8 +1584,10 @@ template("monochrome_public_apk_or_module_tmpl") {
         (!defined(use_trichrome_library) || !use_trichrome_library)
 
     version_name = chrome_version_name
-    if (!experimental_use_r8) {
+    if (experimental_use_r8 == 0) {
       enable_multidex = true
+    } else {
+      use_r8 = true
     }
   }
 }
@@ -1886,8 +1890,10 @@ android_app_bundle("chrome_modern_public_bundle") {
   base_module_target = ":chrome_modern_public_base_module"
   if (!is_java_debug) {
     proguard_enabled = true
-    if (!experimental_use_r8) {
+    if (experimental_use_r8 == 0) {
       enable_multidex = true
+    } else {
+      use_r8 = true
     }
   }
   enable_language_splits = enable_chrome_language_splits
@@ -1906,8 +1912,10 @@ android_app_bundle("monochrome_public_bundle") {
   base_module_target = ":monochrome_public_base_module"
   if (!is_java_debug) {
     proguard_enabled = true
-    if (!experimental_use_r8) {
+    if (experimental_use_r8 == 0) {
       enable_multidex = true
+    } else {
+      use_r8 = true
     }
     proguard_android_sdk_dep = webview_framework_dep
   }