[Offline Pages] Add an observer for requests in the CCT namespace.

chrome/browser/android/offline_pages/cct_request_observer.cc

+// Copyright 2017 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/offline_pages/cct_request_observer.h"
+
+#include "base/android/callback_android.h"
+#include "base/android/jni_int_wrapper.h"
+#include "base/android/jni_string.h"
+#include "chrome/browser/android/app_hooks.h"
+#include "components/offline_pages/core/client_namespace_constants.h"
+#include "components/offline_pages/core/offline_page_feature.h"
+#include "jni/CCTRequestStatus_jni.h"
+
+namespace offline_pages {
+namespace {
+int kCCTRequestObserverUserDataKey;
+}  // namespace
+
+using chrome::android::AppHooks;
+
+// static
+void CCTRequestObserver::AttachToRequestCoordinator(
+    RequestCoordinator* coordinator) {
+  base::android::ScopedJavaLocalRef<jobject> callback =
+      AppHooks::GetOfflinePagesCCTRequestDoneCallback();
+  if (!callback.obj())
+    return;
+
+  auto request_observer = base::WrapUnique(new CCTRequestObserver(callback));
+  coordinator->AddObserver(request_observer.get());
+  coordinator->SetUserData(&kCCTRequestObserverUserDataKey,
+                           std::move(request_observer));
+}
+
+CCTRequestObserver::~CCTRequestObserver() = default;
+CCTRequestObserver::CCTRequestObserver(
+    base::android::ScopedJavaLocalRef<jobject> callback) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  j_callback_.Reset(env, callback.obj());
+}
+
+void CCTRequestObserver::OnAdded(const SavePageRequest& request) {}
+void CCTRequestObserver::OnCompleted(
+    const SavePageRequest& request,
+    RequestNotifier::BackgroundSavePageResult status) {
+  if (request.client_id().name_space != kCCTNamespace) {
+    return;
+  }
+
+  JNIEnv* env = base::android::AttachCurrentThread();
+  base::android::ScopedJavaLocalRef<jobject> callback_info =
+      Java_CCTRequestStatus_create(
+          env, as_jint((int)status),

[chili, 2017/05/23 01:04:00]

what's the difference between static_cast<int> and simply casting as int?

[dewittj, 2017/05/23 16:03:05]

You are right that I should have used static_cast.  I think int is sometimes
problematic because it could mean any of static_cast, const_cast, or
reinterpret_cast.  So we are typically explicit in Chromium.

[David Trainor- moved to gerrit, 2017/05/23 16:53:14]

Yeah IIUC static_cast<> is a more restrictive form of C-style cast and can fail
at compile time.  C-style casts can potentially do bad things at runtime.

+          base::android::ConvertUTF8ToJavaString(env, request.client_id().id));
+
+  base::android::RunCallbackAndroid(j_callback_, callback_info);
+}
+
+void CCTRequestObserver::OnChanged(const SavePageRequest& request) {}
+void CCTRequestObserver::OnNetworkProgress(const SavePageRequest& request,
+                                           int64_t received_bytes) {}
+
+}  // namespace offline_pages