discardable_memory: Using mojo IPC to replace Chrome IPC

components/discardable_memory/service/discardable_shared_memory_manager_proxy.cc

Index: components/discardable_memory/service/discardable_shared_memory_manager_proxy.cc
diff --git a/components/discardable_memory/service/discardable_shared_memory_manager_proxy.cc b/components/discardable_memory/service/discardable_shared_memory_manager_proxy.cc
new file mode 100644
index 0000000000000000000000000000000000000000..68cae498e45fa2d074f9de0aa359bd4cf63cc008
--- /dev/null
+++ b/components/discardable_memory/service/discardable_shared_memory_manager_proxy.cc
@@ -0,0 +1,57 @@
+// Copyright 2016 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 "components/discardable_memory/service/discardable_shared_memory_manager_proxy.h"
+
+#include "components/discardable_memory/service/discardable_shared_memory_manager.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+#include "mojo/public/cpp/system/platform_handle.h"
+
+namespace discardable_memory {
+
+int DiscardableSharedMemoryManagerProxy::last_client_id_ = 0;

[reveman, 2016/11/15 16:13:20]

I'd still prefer to see this as a member of the DiscardableSharedMemoryManager
class and the client id passed as a ctor argument to the proxy instance. Is that
possible?

[Peng, 2016/11/15 19:04:05]

Done.

+
+DiscardableSharedMemoryManagerProxy::DiscardableSharedMemoryManagerProxy()
+    : client_id_(++last_client_id_),
+      manager_(
+          ::discardable_memory::DiscardableSharedMemoryManager::current()) {}

[reveman, 2016/11/15 16:13:20]

why can't the manager be passed as an argument instead of having to use
DiscardableSharedMemoryManager::current()?

[Peng, 2016/11/15 19:04:05]

Done.

+
+DiscardableSharedMemoryManagerProxy::~DiscardableSharedMemoryManagerProxy() {
+  CHECK_EQ(manager_,

[reveman, 2016/11/15 16:13:20]

what's the purpose of all these CHECKs?

[Peng, 2016/11/15 19:04:05]

Removed them.

+           ::discardable_memory::DiscardableSharedMemoryManager::current());
+  manager_->ClientRemoved(client_id_);
+}
+
+// static
+void DiscardableSharedMemoryManagerProxy::Create(
+    mojom::DiscardableSharedMemoryManagerRequest request) {
+  mojo::MakeStrongBinding(
+      base::MakeUnique<DiscardableSharedMemoryManagerProxy>(),
+      std::move(request));
+}
+
+void DiscardableSharedMemoryManagerProxy::AllocateLockedDiscardableSharedMemory(
+    uint32_t size,
+    int32_t id,
+    const AllocateLockedDiscardableSharedMemoryCallback& callback) {
+  CHECK_EQ(manager_,
+           ::discardable_memory::DiscardableSharedMemoryManager::current());
+  base::SharedMemoryHandle handle;
+  manager_->AllocateLockedDiscardableSharedMemoryForClient(client_id_, size, id,
+                                                           &handle);
+  mojo::ScopedSharedBufferHandle memory;
+  if (handle != base::SharedMemory::NULLHandle()) {
+    memory = mojo::WrapSharedMemoryHandle(handle, size, false /* ready_only */);
+  }
+  return callback.Run(std::move(memory));
+}
+
+void DiscardableSharedMemoryManagerProxy::DeletedDiscardableSharedMemory(
+    int32_t id) {
+  CHECK_EQ(manager_,
+           ::discardable_memory::DiscardableSharedMemoryManager::current());
+  manager_->ClientDeletedDiscardableSharedMemory(id, client_id_);
+}
+
+}  // namespace discardable_memory