Add the Errorprone Java Compiler

These changes let the errorprone compiler find problems when building Android.
A global flag disabled Errorprone by default.

When enabled, code problems will be shown with suggestions on how to fix them.

BUG=485599

Review URL: https://codereview.chromium.org/1136573002

Cr-Commit-Position: refs/heads/master@{#335509}

3 files changed, 33 insertions, 1 deletions

diff --git a/build/config/android/config.gni b/build/config/android/config.gni
index e74e8fe..d6a8ad5 100644
--- a/build/config/android/config.gni
+++ b/build/config/android/config.gni
@@ -42,6 +42,9 @@ if (is_android) {
 
     # Set to true to run findbugs on JAR targets.
     run_findbugs = false
+
+    # Set to true to enable the Errorprone compiler
+    use_errorprone_java_compiler = false
   }
 
   # Host stuff -----------------------------------------------------------------
diff --git a/build/config/android/internal_rules.gni b/build/config/android/internal_rules.gni
index 0933ceb..1988d8f 100644
--- a/build/config/android/internal_rules.gni
+++ b/build/config/android/internal_rules.gni
@@ -909,6 +909,12 @@ template("compile_java") {
   if (defined(invoker.chromium_code)) {
     _chromium_code = invoker.chromium_code
   }
+
+  _enable_errorprone = use_errorprone_java_compiler
+  if (defined(invoker.enable_errorprone)) {
+    _enable_errorprone = invoker.enable_errorprone
+  }
+
   _manifest_entries = []
   if (defined(invoker.manifest_entries)) {
     _manifest_entries = invoker.manifest_entries
@@ -978,7 +984,13 @@ template("compile_java") {
     if (_chromium_code) {
       args += [ "--chromium-code=1" ]
     }
-
+    if (_enable_errorprone) {
+      deps += [ "//third_party/errorprone:chromium_errorprone" ]
+      args += [
+        "--use-errorprone-path",
+        "bin/chromium_errorprone",
+      ]
+    }
     args += rebase_path(_java_files, root_build_dir)
   }
 
@@ -1128,6 +1140,9 @@ template("java_library_impl") {
     chromium_code = _chromium_code
     android = _requires_android
 
+    if (defined(invoker.enable_errorprone)) {
+      _enable_errorprone = invoker.enable_errorprone
+    }
     if (defined(invoker.jar_excluded_patterns)) {
       jar_excluded_patterns = invoker.jar_excluded_patterns
     }
diff --git a/build/config/android/rules.gni b/build/config/android/rules.gni
index 4c22fac..b831c09 100644
--- a/build/config/android/rules.gni
+++ b/build/config/android/rules.gni
@@ -798,6 +798,7 @@ template("java_strings_grd_prebuilt") {
 #     android_library target, for example.
 #
 #   chromium_code: If true, extra analysis warning/errors will be enabled.
+#   enable_errorprone: If true, enables the errorprone compiler.
 #
 #   data_deps, testonly
 #
@@ -825,6 +826,9 @@ template("java_binary") {
     if (defined(invoker.deps)) {
       deps = invoker.deps
     }
+    if (defined(invoker.enable_errorprone)) {
+      enable_errorprone = invoker.enable_errorprone
+    }
     if (defined(invoker.java_files)) {
       java_files = invoker.java_files
     }
@@ -919,6 +923,8 @@ template("junit_binary") {
 #     ease the gyp->gn conversion and will be removed in the future.
 #
 #   chromium_code: If true, extra analysis warning/errors will be enabled.
+#   enable_errorprone: If true, enables the errorprone compiler.
+#
 #   jar_excluded_patterns: List of patterns of .class files to exclude from the
 #     final jar.
 #
@@ -967,6 +973,9 @@ template("java_library") {
     if (defined(invoker.deps)) {
       deps = invoker.deps
     }
+    if (defined(invoker.enable_errorprone)) {
+      enable_errorprone = invoker.enable_errorprone
+    }
     if (defined(invoker.jar_excluded_patterns)) {
       jar_excluded_patterns = invoker.jar_excluded_patterns
     }
@@ -1058,6 +1067,8 @@ template("java_prebuilt") {
 #     ease the gyp->gn conversion and will be removed in the future.
 #
 #   chromium_code: If true, extra analysis warning/errors will be enabled.
+#   enable_errorprone: If true, enables the errorprone compiler.
+#
 #   jar_excluded_patterns: List of patterns of .class files to exclude from the
 #     final jar.
 #
@@ -1103,6 +1114,9 @@ template("android_library") {
     if (defined(invoker.deps)) {
       deps = invoker.deps
     }
+    if (defined(invoker.enable_errorprone)) {
+      enable_errorprone = invoker.enable_errorprone
+    }
     if (defined(invoker.jar_excluded_patterns)) {
       jar_excluded_patterns = invoker.jar_excluded_patterns
     }