Refactor ActivityStatus to not store current activity

base/base.gyp

Index: base/base.gyp
diff --git a/base/base.gyp b/base/base.gyp
index 78e6ddb0227291275a47d6c275fc4ff9704272ad..fd77f1c3496ed3d6e3e94784eb43317b35404aee 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -447,7 +447,7 @@
       'type': '<(gtest_target_type)',
       'sources': [
         # Tests.
-        'android/activity_status_unittest.cc',
+        'android/application_status_listener_unittest.cc',
         'android/jni_android_unittest.cc',
         'android/jni_array_unittest.cc',
         'android/jni_string_unittest.cc',
@@ -1312,6 +1312,7 @@
           },
           'dependencies': [
             'base_java_activity_state',
+            'base_java_application_state',
             'base_java_memory_pressure_level_list',
             'base_native_libraries_gen',
           ],
@@ -1352,6 +1353,22 @@
           'includes': [ '../build/android/java_cpp_template.gypi' ],
         },
         {
+          'target_name': 'base_java_application_state',
+          'type': 'none',
+          # This target is used to auto-generate ApplicationState.java
+          # from a template file. The source file contains a list of
+          # Java constant declarations matching the ones in
+          # android/application_state_list.h.
+          'sources': [
+            'android/java/src/org/chromium/base/ApplicationState.template',
+          ],
+          'variables': {
+            'package_name': 'org/chromium/base',
+            'template_deps': ['android/application_state_list.h'],
+          },
+          'includes': [ '../build/android/java_cpp_template.gypi' ],
+        },
+        {
           'target_name': 'base_java_memory_pressure_level_list',
           'type': 'none',
           'sources': [