Rewrite the Android implementation of BatteryMonitor directly in Java.

device/battery/battery.gyp

Index: device/battery/battery.gyp
diff --git a/device/battery/battery.gyp b/device/battery/battery.gyp
index f8bbb1975412acbdde31684dd220fa613e2e20e7..9ecaa71f2749d99625394c92a09a861545e6bdee 100644
--- a/device/battery/battery.gyp
+++ b/device/battery/battery.gyp
@@ -20,6 +20,35 @@
       ],
     },
     {
+      # This is needed only for a build within Android tree. TODO(ppi): remove
+      # when Android tree build is deprecated.
+      'target_name': 'device_battery_mojo_bindings_for_webview',
+      'type': 'none',
+      'dependencies': [
+        'device_battery_mojo_bindings',
+      ],
+      'actions': [
+        {
+          # Dummy action that triggers the bindings generation and explicitly
+          # declares the java outputs, so that they are discoverable to make.
+          'action_name': 'device_battery_mojo_bindings_dummy_action',
+          'inputs': [
+            '<(SHARED_INTERMEDIATE_DIR)/device/battery/battery_monitor.mojom.h',
+            '<(SHARED_INTERMEDIATE_DIR)/device/battery/battery_status.mojom.h',
+          ],
+          'outputs': [
+            '<(SHARED_INTERMEDIATE_DIR)/java_mojo/device_battery_mojo_bindings/src/org/chromium/mojom/device/BatteryMonitor.java',
+            '<(SHARED_INTERMEDIATE_DIR)/java_mojo/device_battery_mojo_bindings/src/org/chromium/mojom/device/BatteryMonitor_Internal.java',
+            '<(SHARED_INTERMEDIATE_DIR)/java_mojo/device_battery_mojo_bindings/src/org/chromium/mojom/device/BatteryStatusObserver.java',
+            '<(SHARED_INTERMEDIATE_DIR)/java_mojo/device_battery_mojo_bindings/src/org/chromium/mojom/device/BatteryStatusObserver_Internal.java',
+            '<(SHARED_INTERMEDIATE_DIR)/java_mojo/device_battery_mojo_bindings/src/org/chromium/mojom/device/BatteryStatus.java',
+          ],
+          'action': ['python', '--version'],

[Torne, 2014/12/18 16:20:47]

Not sure if this will actually make a difference in practise, but I would
suggest making the action here ['touch', '<@(_outputs)'] so that it will
actually ensure that the output files are newer than the inputs. The android
tree build is using make and so doesn't ahve ninja's restat behaviour that makes
it "okay" to not actually update all your outputs.

It might not really matter but I don't think it hurts :)

[ppi, 2014/12/18 16:54:15]

Neat:), done.

+        },
+      ],
+      'hard_dependency': 1,
+    },
+    {
       # GN version: //device/battery
       'target_name': 'device_battery',
       'type': '<(component)',
@@ -35,12 +64,8 @@
         'DEVICE_BATTERY_IMPLEMENTATION',
       ],
       'sources': [
-        'android/battery_jni_registrar.cc',
-        'android/battery_jni_registrar.h',
         'battery_monitor_impl.cc',
         'battery_monitor_impl.h',
-        'battery_status_manager_android.cc',
-        'battery_status_manager_android.h',
         'battery_status_manager_chromeos.cc',
         'battery_status_manager_default.cc',
         'battery_status_manager_linux.cc',
@@ -53,14 +78,6 @@
         'battery_status_service.h',
       ],
       'conditions': [
-        ['OS == "android"', {
-          'dependencies': [
-            'device_battery_jni_headers',
-          ],
-          'sources!': [
-            'battery_status_manager_default.cc',
-          ],
-        }],
         ['chromeos==1', {
           'dependencies': [
             '../../build/linux/system.gyp:dbus',
@@ -101,21 +118,12 @@
     ['OS == "android"', {
       'targets': [
         {
-          'target_name': 'device_battery_jni_headers',
-          'type': 'none',
-          'sources': [
-            'android/java/src/org/chromium/device/battery/BatteryStatusManager.java',
-          ],
-          'variables': {
-            'jni_gen_package': 'device_battery',
-          },
-          'includes': [ '../../build/jni_generator.gypi' ],
-        },
-        {
           'target_name': 'device_battery_java',
           'type': 'none',
           'dependencies': [
             '../../base/base.gyp:base',
+            '../../mojo/mojo_public.gyp:mojo_bindings_java',
+            'device_battery_mojo_bindings',
           ],
           'variables': {
             'java_in_dir': '../../device/battery/android/java',