discardable_memory: Using mojo IPC to replace Chrome IPC

content/ppapi_plugin/ppapi_thread.cc

Index: content/ppapi_plugin/ppapi_thread.cc
diff --git a/content/ppapi_plugin/ppapi_thread.cc b/content/ppapi_plugin/ppapi_thread.cc
index 5829f837086061c51d729fed63072f4311e472b5..0f23b4ad624c657ce20d3140a059ce486694d12e 100644
--- a/content/ppapi_plugin/ppapi_thread.cc
+++ b/content/ppapi_plugin/ppapi_thread.cc
@@ -48,6 +48,7 @@
 #include "ppapi/proxy/plugin_message_filter.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/resource_reply_thread_registrar.h"
+#include "services/service_manager/public/cpp/interface_provider.h"
 #include "third_party/WebKit/public/web/WebKit.h"
 #include "ui/base/ui_base_switches.h"
 
@@ -130,8 +131,14 @@ PpapiThread::PpapiThread(const base::CommandLine& command_line, bool is_broker)
   // In single process, browser main loop set up the discardable memory
   // allocator.
   if (!command_line.HasSwitch(switches::kSingleProcess)) {
+    discardable_memory::mojom::DiscardableSharedMemoryManagerPtr manager_ptr;
+    ChildThread::Get()->GetRemoteInterfaces()->GetInterface(
+        mojo::GetProxy(&manager_ptr));
+    discardable_shared_memory_manager_ = base::MakeUnique<
+        discardable_memory::ClientDiscardableSharedMemoryManager>(
+        manager_ptr.PassInterface(), GetIOTaskRunner().get());

[dcheng, 2016/11/25 00:07:08]

Nit: the fact that we end up rebinding this interface pointer on a different
thread is an implementation detail. I would just std::move() here, and use
PassInterface() inside ClientDiscardableSharedMemoryManager.

[Peng, 2016/11/25 16:41:53]

Done.

     base::DiscardableMemoryAllocator::SetInstance(
-        ChildThreadImpl::discardable_shared_memory_manager());
+        discardable_shared_memory_manager_.get());
   }
 }