GN: Make _incremental apk targets work when no <application> exists

build/android/incremental_install/generate_android_manifest.py

Index: build/android/incremental_install/generate_android_manifest.py
diff --git a/build/android/incremental_install/generate_android_manifest.py b/build/android/incremental_install/generate_android_manifest.py
index b9061ed89fa87079c38371290501b055b33e604f..17eabd4d9ab8ba6d7372c30e7375de1bb36ecce8 100755
--- a/build/android/incremental_install/generate_android_manifest.py
+++ b/build/android/incremental_install/generate_android_manifest.py
@@ -22,6 +22,7 @@ ElementTree.register_namespace('android', _ANDROID_NAMESPACE)
 
 _INCREMENTAL_APP_NAME = 'org.chromium.incrementalinstall.BootstrapApplication'
 _META_DATA_NAME = 'incremental-install-real-app'
+_DEFAULT_APPLICATION_CLASS = 'android.app.Application'
 
 
 def _AddNamespace(name):
@@ -44,13 +45,11 @@ def _ParseArgs():
   return parser.parse_args()
 
 
-def _ProcessManifest(main_manifest, main_manifest_path,
-                     disable_isolated_processes):
+def _ProcessManifest(main_manifest, disable_isolated_processes):
   """Returns a transformed AndroidManifest.xml for use with _incremental apks.
 
   Args:
     main_manifest: Manifest contents to transform.
-    main_manifest_path: Path to main_manifest (used for error messages).
     disable_isolated_processes: Whether to set all isolatedProcess attributes to
         false
 
@@ -64,11 +63,10 @@ def _ProcessManifest(main_manifest, main_manifest_path,
   doc = ElementTree.fromstring(main_manifest)
   app_node = doc.find('application')
   if app_node is None:
-    raise Exception('Could not find <application> in %s' % main_manifest_path)
-  real_app_class = app_node.get(_AddNamespace('name'))
-  if real_app_class is None:
-    raise Exception('Could not find android:name in <application> in %s' %
-                    main_manifest_path)
+    app_node = ElementTree.SubElement(doc, 'application')
+
+  real_app_class = app_node.get(_AddNamespace('name'),
+                                _DEFAULT_APPLICATION_CLASS)
   app_node.set(_AddNamespace('name'), _INCREMENTAL_APP_NAME)
 
   meta_data_node = ElementTree.SubElement(app_node, 'meta-data')
@@ -81,7 +79,7 @@ def main():
   options = _ParseArgs()
   with open(options.src_manifest) as f:
     main_manifest_data = f.read()
-  new_manifest_data = _ProcessManifest(main_manifest_data, options.src_manifest,
+  new_manifest_data = _ProcessManifest(main_manifest_data,
                                        options.disable_isolated_processes)
   with open(options.out_manifest, 'w') as f:
     f.write(new_manifest_data)