Clear webapp storage when site data is cleared

chrome/browser/android/webapps/webapp_registry.cc

Index: chrome/browser/android/webapps/webapp_registry.cc
diff --git a/chrome/browser/android/webapps/webapp_registry.cc b/chrome/browser/android/webapps/webapp_registry.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ffa9404389915819102e2ded3a1173ef01280cf4
--- /dev/null
+++ b/chrome/browser/android/webapps/webapp_registry.cc
@@ -0,0 +1,41 @@
+// Copyright 2015 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.
+
+#include "chrome/browser/android/webapps/webapp_registry.h"
+
+#include <jni.h>
+
+#include "base/android/jni_android.h"
+#include "base/callback.h"
+#include "chrome/browser/io_thread.h"
+#include "content/public/browser/browser_thread.h"
+#include "jni/WebappRegistry_jni.h"
+
+// static
+void WebappRegistry::UnregisterWebapps(
+    const base::Closure& callback) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  uintptr_t callback_pointer = reinterpret_cast<uintptr_t>(
+      new base::Closure(callback));
+
+  Java_WebappRegistry_unregisterAllWebapps(
+      env,
+      base::android::GetApplicationContext(),
+      callback_pointer);
+}
+
+// Callback used by Java when all webapps have been unregistered.
+// Declared in JNI header file.

[gone, 2015/09/09 23:30:40]

nit: remove unhelpful "Declared in JNI header" comment

[Lalit Maganti, 2015/09/10 09:41:58]

Done.

+void OnWebappsUnregistered(JNIEnv* env,
+                           const JavaParamRef<jclass>& klass,
+                           jlong jcallback) {
+  base::Closure* callback = reinterpret_cast<base::Closure*>(jcallback);

[gone, 2015/09/09 23:30:40]

again, my familiarity with native code is lacking, but is it possible for this
callback to have become invalid in between when the java call was made and when
this function is called?

[Lalit Maganti, 2015/09/10 09:41:57]

AFAIK: no the pointer cannot be invalid until delete is called on it. And the
only place where delete is called is after the callback is run.

+  callback->Run();
+  delete callback;
+}
+
+// static
+bool WebappRegistry::RegisterWebappRegistry(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}