Revert of discardable_memory: Using mojo IPC to replace Chrome IPC

components/discardable_memory/client/client_discardable_shared_memory_manager.h

Index: components/discardable_memory/client/client_discardable_shared_memory_manager.h
diff --git a/components/discardable_memory/client/client_discardable_shared_memory_manager.h b/components/discardable_memory/client/client_discardable_shared_memory_manager.h
index 93676a61701bac7378d11816bbbe509a09a15c3c..76215bc099f65ccd6cd36299f09ea531b29b1a4a 100644
--- a/components/discardable_memory/client/client_discardable_shared_memory_manager.h
+++ b/components/discardable_memory/client/client_discardable_shared_memory_manager.h
@@ -7,7 +7,6 @@
 
 #include <stddef.h>
 
-#include "base/callback_helpers.h"
 #include "base/macros.h"
 #include "base/memory/discardable_memory_allocator.h"
 #include "base/memory/ref_counted.h"
@@ -16,11 +15,7 @@
 #include "base/trace_event/memory_dump_provider.h"
 #include "components/discardable_memory/common/discardable_memory_export.h"
 #include "components/discardable_memory/common/discardable_shared_memory_heap.h"
-#include "components/discardable_memory/public/interfaces/discardable_shared_memory_manager.mojom.h"
-
-namespace base {
-class SingleThreadTaskRunner;
-}
+#include "components/discardable_memory/common/discardable_shared_memory_id.h"
 
 namespace discardable_memory {
 
@@ -30,9 +25,20 @@
     : public base::DiscardableMemoryAllocator,
       public base::trace_event::MemoryDumpProvider {
  public:
-  ClientDiscardableSharedMemoryManager(
-      mojom::DiscardableSharedMemoryManagerPtr manager,
-      scoped_refptr<base::SingleThreadTaskRunner> io_task_runner);
+  class Delegate {
+   public:
+    virtual void AllocateLockedDiscardableSharedMemory(
+        size_t size,
+        DiscardableSharedMemoryId id,
+        base::SharedMemoryHandle* handle) = 0;
+    virtual void DeletedDiscardableSharedMemory(
+        DiscardableSharedMemoryId id) = 0;
+
+   protected:
+    virtual ~Delegate() {}
+  };
+
+  explicit ClientDiscardableSharedMemoryManager(Delegate* delegate);
   ~ClientDiscardableSharedMemoryManager() override;
 
   // Overridden from base::DiscardableMemoryAllocator:
@@ -64,25 +70,14 @@
 
  private:
   std::unique_ptr<base::DiscardableSharedMemory>
-  AllocateLockedDiscardableSharedMemory(size_t size, int32_t id);
-  void AllocateOnIO(size_t size,
-                    int32_t id,
-                    std::unique_ptr<base::DiscardableSharedMemory>* memory,
-                    base::ScopedClosureRunner closure_runner);
-  void AllocateCompletedOnIO(
-      std::unique_ptr<base::DiscardableSharedMemory>* memory,
-      base::ScopedClosureRunner closure_runner,
-      mojo::ScopedSharedBufferHandle mojo_handle);
-
-  void DeletedDiscardableSharedMemory(int32_t id);
+  AllocateLockedDiscardableSharedMemory(size_t size,
+                                        DiscardableSharedMemoryId id);
   void MemoryUsageChanged(size_t new_bytes_allocated,
                           size_t new_bytes_free) const;
 
-  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
-  std::unique_ptr<mojom::DiscardableSharedMemoryManagerPtr> manager_mojo_;
-
   mutable base::Lock lock_;
-  std::unique_ptr<DiscardableSharedMemoryHeap> heap_;
+  DiscardableSharedMemoryHeap heap_;
+  Delegate* const delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(ClientDiscardableSharedMemoryManager);
 };