Revert of discardable_memory: Using mojo IPC to replace Chrome IPC

content/child/child_thread_impl.cc

Index: content/child/child_thread_impl.cc
diff --git a/content/child/child_thread_impl.cc b/content/child/child_thread_impl.cc
index 2fba1bee8a04cd46510cc2a77c281ca2774dee5b..7f2755b3e00f3859bfe499adb57561c2686db6ca 100644
--- a/content/child/child_thread_impl.cc
+++ b/content/child/child_thread_impl.cc
@@ -32,6 +32,7 @@
 #include "base/timer/elapsed_timer.h"
 #include "base/tracked_objects.h"
 #include "build/build_config.h"
+#include "components/discardable_memory/client/client_discardable_shared_memory_manager.h"
 #include "components/tracing/child/child_trace_message_filter.h"
 #include "content/child/child_histogram_message_filter.h"
 #include "content/child/child_process.h"
@@ -317,7 +318,8 @@
 }
 
 ChildThreadImpl::Options::Builder&
-ChildThreadImpl::Options::Builder::ConnectToBrowser(bool connect_to_browser) {
+ChildThreadImpl::Options::Builder::ConnectToBrowser(
+  bool connect_to_browser) {
   options_.connect_to_browser = connect_to_browser;
   return *this;
 }
@@ -353,6 +355,33 @@
 #endif
   return handled;
 }
+
+class ChildThreadImpl::ClientDiscardableSharedMemoryManagerDelegate
+    : public discardable_memory::ClientDiscardableSharedMemoryManager::
+          Delegate {
+ public:
+  explicit ClientDiscardableSharedMemoryManagerDelegate(
+      scoped_refptr<ThreadSafeSender> sender)
+      : sender_(sender) {}
+  ~ClientDiscardableSharedMemoryManagerDelegate() override {}
+
+  void AllocateLockedDiscardableSharedMemory(
+      size_t size,
+      discardable_memory::DiscardableSharedMemoryId id,
+      base::SharedMemoryHandle* handle) override {
+    sender_->Send(
+        new ChildProcessHostMsg_SyncAllocateLockedDiscardableSharedMemory(
+            size, id, handle));
+  }
+
+  void DeletedDiscardableSharedMemory(
+      discardable_memory::DiscardableSharedMemoryId id) override {
+    sender_->Send(new ChildProcessHostMsg_DeletedDiscardableSharedMemory(id));
+  }
+
+ private:
+  scoped_refptr<ThreadSafeSender> sender_;
+};
 
 ChildThreadImpl::ChildThreadImpl()
     : route_provider_binding_(this),
@@ -377,7 +406,7 @@
   Init(options);
 }
 
-scoped_refptr<base::SingleThreadTaskRunner> ChildThreadImpl::GetIOTaskRunner() {
+scoped_refptr<base::SequencedTaskRunner> ChildThreadImpl::GetIOTaskRunner() {
   if (IsInBrowserProcess())
     return browser_process_io_runner_;
   return ChildProcess::current()->io_task_runner();
@@ -564,6 +593,13 @@
 
   shared_bitmap_manager_.reset(
       new ChildSharedBitmapManager(thread_safe_sender()));
+
+  client_discardable_shared_memory_manager_delegate_ =
+      base::MakeUnique<ClientDiscardableSharedMemoryManagerDelegate>(
+          thread_safe_sender());
+  discardable_shared_memory_manager_ = base::MakeUnique<
+      discardable_memory::ClientDiscardableSharedMemoryManager>(
+      client_discardable_shared_memory_manager_delegate_.get());
 }
 
 ChildThreadImpl::~ChildThreadImpl() {
@@ -592,6 +628,10 @@
   file_system_dispatcher_.reset();
   quota_dispatcher_.reset();
   WebFileSystemImpl::DeleteThreadSpecificInstance();
+}
+
+void ChildThreadImpl::ShutdownDiscardableSharedMemoryManager() {
+  discardable_shared_memory_manager_.reset();
 }
 
 void ChildThreadImpl::OnChannelConnected(int32_t peer_pid) {