Use the new java_cpp_enum rule in content.

content/public/android/BUILD.gn

 # Copyright 2014 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("//build/config/android/config.gni")
 import("//build/config/android/rules.gni")
 
 content_jni_gypi_values = exec_script("//build/gypi_to_gn.py",
     [ rebase_path("../../content_jni.gypi") ],
     "scope",
@@ skipping 24 matching lines @@
     "//media/base/android:media_java",
     "//net/android:net_java",
     "//ui/android:ui_java",
     "//third_party/jsr-305:jsr_305_javalib",
 
 #"//content:content_common",
   ]
 
   srcjar_deps = [
     ":common_aidl",
-    ":content_gamepad_mapping_java",
-    ":gesture_event_type_java",
-    ":popup_item_type_java",
-    ":result_codes_java",
-    ":selection_event_type_java",
-    ":speech_recognition_error_java",
-    ":top_controls_state_java",
-    ":screen_orientation_values_java",
+    ":content_public_android_java_enums_srcjar",
   ]
 
   DEPRECATED_java_in_dir = "java/src"
   if (!is_android_webview_build) {
     deps += [
       "//third_party/eyesfree:eyesfree_java",
     ]
   }
 }
 
@@ skipping 40 matching lines @@
     "values-sw/android_content_strings.xml",
     "values-th/android_content_strings.xml",
     "values-tr/android_content_strings.xml",
     "values-uk/android_content_strings.xml",
     "values-vi/android_content_strings.xml",
     "values-zh-rCN/android_content_strings.xml",
     "values-zh-rTW/android_content_strings.xml",
   ]
 }
 
-java_cpp_template("gesture_event_type_java") {
+java_cpp_enum("content_public_android_java_enums_srcjar") {
   sources = [
-    "java/src/org/chromium/content/browser/GestureEventType.template",
+    "//content/browser/android/content_view_core_impl.cc",
+    "//content/browser/android/gesture_event_type.h",
+    "//content/browser/renderer_host/input/selection_event_type.h",
+    "//content/browser/gamepad/gamepad_standard_mappings.h",
+    "//content/public/common/result_codes.h",
+    "//content/public/common/screen_orientation_values.h",
+    "//content/public/common/speech_recognition_error.h",
+    "//content/public/common/top_controls_state.h",
   ]
-  package_name = "org/chromium/content/browser"
-  inputs = [
-    "//content/browser/android/gesture_event_type_list.h"
+  outputs = [
+    "org/chromium/content/browser/GestureEventType.java",
+    "org/chromium/content/browser/input/CanonicalAxisIndex.java",
+    "org/chromium/content/browser/input/CanonicalButtonIndex.java",
+    "org/chromium/content/browser/input/PopupItemType.java",
+    "org/chromium/content/browser/input/SelectionEventType.java",
+    "org/chromium/content_public/common/ResultCode.java",
+    "org/chromium/content_public/common/ScreenOrientationValues.java",
+    "org/chromium/content_public/common/SpeechRecognitionErrorCode.java",
+    "org/chromium/content_public/common/TopControlsState.java",
   ]
 }
 
-java_cpp_template("popup_item_type_java") {
-  sources = [
-    "java/src/org/chromium/content/browser/input/PopupItemType.template",
-  ]
-  package_name = "org/chromium/content/browser/input"
-  inputs = [
-    "//content/browser/android/popup_item_type_list.h"
-  ]
-}
-
-java_cpp_template("result_codes_java") {
-  sources = [
-    "java/src/org/chromium/content/common/ResultCodes.template",
-  ]
-  package_name = "org/chromium/content/common"
-  inputs = [
-    "//content/public/common/result_codes_list.h"
-  ]
-}
-
-java_cpp_template("selection_event_type_java") {
-  sources = [
-    "java/src/org/chromium/content/browser/input/SelectionEventType.template",
-  ]
-  package_name = "org/chromium/content/browser/input"
-  inputs = [
-    "//content/browser/renderer_host/input/selection_event_type_list.h"
-  ]
-}
-
-java_cpp_template("speech_recognition_error_java") {
-  sources = [
-    "java/src/org/chromium/content/browser/SpeechRecognitionError.template",
-  ]
-  package_name = "org/chromium/content/browser"
-  inputs = [
-    "//content/public/common/speech_recognition_error_list.h"
-  ]
-}
-
-java_cpp_template("top_controls_state_java") {
-  sources = [
-    "java/src/org/chromium/content/common/TopControlsState.template",
-  ]
-  package_name = "org/chromium/content/common"
-  inputs = [
-    "//content/public/common/top_controls_state_list.h"
-  ]
-}
-
-java_cpp_template("screen_orientation_values_java") {
-  sources = [
-    "java/src/org/chromium/content_public/common/ScreenOrientationValues.template",
-  ]
-  package_name = "org/chromium/content_public/common"
-  inputs = [
-    "//content/public/common/screen_orientation_values_list.h"
-  ]
-}
-
-java_cpp_template("content_gamepad_mapping_java") {
-  sources = [
-    "java/src/org/chromium/content/browser/input/CanonicalAxisIndex.template",
-    "java/src/org/chromium/content/browser/input/CanonicalButtonIndex.template",
-  ]
-  package_name = "org/chromium/content/common"
-  inputs = [
-    "//content/browser/gamepad/canonical_axis_index_list.h",
-    "//content/browser/gamepad/canonical_button_index_list.h",
-  ]
-}
-
 generate_jar_jni("jar_jni") {
   jni_package = "content"
   classes = [
     "java/util/HashSet.class",
     "android/view/MotionEvent.class",
   ]
 }
 
 generate_jni("content_jni_headers") {
   sources = rebase_path(content_jni_gypi_values.sources, "", "../..")
@@ skipping 22 matching lines @@
     "//net/android:net_java_test_support",
     "//ui/android:ui_java",
     ":content_java",
   ]
 
   DEPRECATED_java_in_dir = "javatests/src"
 }
 
 
 # TODO(GYP): content_icudata