Use the Errorprone Compiler

build/java_apk.gypi

Index: build/java_apk.gypi
diff --git a/build/java_apk.gypi b/build/java_apk.gypi
index ab415a9ad624b443dbaf14ea99649a9a4055e882..9027d9fc21e55fc18c8d3ce1ad1d1cbdb25fb174 100644
--- a/build/java_apk.gypi
+++ b/build/java_apk.gypi
@@ -181,6 +181,8 @@
     'extra_native_libs': [],
     'native_lib_placeholder_stamp': '<(apk_package_native_libs_dir)/<(android_app_abi)/native_lib_placeholder.stamp',
     'native_lib_placeholders': [],
+    'enable_errorprone%': '1',
+    'errorprone_exe_path': '<(PRODUCT_DIR)/bin.java/chromium_errorprone',
   },
   # Pass the jar path to the apk's "fake" jar target.  This would be better as
   # direct_dependent_settings, but a variable set by a direct_dependent_settings
@@ -223,6 +225,11 @@
         '<(DEPTH)/base/base.gyp:chromium_android_linker',
       ],
     }],
+    ['enable_errorprone == 1', {
+      'dependencies': [
+        '<(DEPTH)/third_party/errorprone/errorprone.gyp:chromium_errorprone',
+      ],
+    }],
     ['native_lib_target != ""', {
       'variables': {
         'conditions': [
@@ -678,7 +685,14 @@
         # targets use the same java_in_dir and both use java_apk.gypi or
         # both use java.gypi.)
         'java_sources': ['>!@(find >(java_in_dir)>(java_in_dir_suffix) >(additional_src_dirs) -name "*.java"  # apk)'],
-
+        'conditions': [
+          ['enable_errorprone == 1', {
+            'extra_inputs': [
+              '<(errorprone_exe_path)',
+            ],
+            'extra_args': [ '--use-errorprone-path=<(errorprone_exe_path)' ],
+          }],
+        ],
       },
       'inputs': [
         '<(DEPTH)/build/android/gyp/util/build_utils.py',
@@ -686,6 +700,7 @@
         '>@(java_sources)',
         '>@(input_jars_paths)',
         '<(codegen_stamp)',
+        '<@(extra_inputs)',
       ],
       'conditions': [
         ['native_lib_target != ""', {
@@ -705,6 +720,7 @@
         '--jar-path=<(javac_jar_path)',
         '--jar-excluded-classes=<(jar_excluded_classes)',
         '--stamp=<(compile_stamp)',
+        '<@(extra_args)',
         '>@(java_sources)',
       ],
     },