Implement in-process PPB_VarArrayBuffer_Dev.

ppapi/shared_impl/var_tracker.h

 // Copyright (c) 2011 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.
 
 #ifndef PPAPI_SHARED_IMPL_VAR_TRACKER_H_
 #define PPAPI_SHARED_IMPL_VAR_TRACKER_H_
 
 #include "base/basictypes.h"
 #include "base/hash_tables.h"
 #include "base/memory/ref_counted.h"
+#include "ppapi/c/pp_module.h"
 #include "ppapi/c/pp_var.h"
 #include "ppapi/shared_impl/ppapi_shared_export.h"
 
 namespace ppapi {
 
+class ArrayBufferVar;
 class Var;
 
 // Tracks non-POD (refcounted) var objects held by a plugin.
 //
 // The tricky part is the concept of a "tracked object". These are only
 // necessary in the plugin side of the proxy when running out of process. A
 // tracked object is one that the plugin is aware of, but doesn't hold a
 // reference to. This will happen when the plugin is passed an object as an
 // argument from the host (renderer) as an input argument to a sync function,
 // but where ownership is not passed.
@@ skipping 21 matching lines @@
   bool AddRefVar(int32 var_id);
   bool AddRefVar(const PP_Var& var);
 
   // Decreases the given Var ID's refcount, returning true on success, false if
   // the ID is invalid or if the refcount was already 0. The PP_Var version
   // returns true and does nothing for non-refcounted type vars. The var will
   // be deleted if there are no more refs to it.
   bool ReleaseVar(int32 var_id);
   bool ReleaseVar(const PP_Var& var);
 
+  // Create a new array buffer of size |size_in_bytes|. Return a PP_Var that
+  // that references it and has an initial reference-count of 1.
+  PP_Var MakeArrayBufferPPVar(uint32 size_in_bytes);
+
  protected:
   struct VarInfo {
     VarInfo();
     VarInfo(Var* v, int input_ref_count);
 
     scoped_refptr<Var> var;
 
     // Explicit reference count. This value is affected by the renderer calling
     // AddRef and Release. A nonzero value here is represented by a single
     // reference in the host on our behalf (this reduces IPC traffic).
@@ skipping 52 matching lines @@
   // still alive.
   //
   // Overridden by the PluginVarTracker to also clean up the host info map.
   virtual bool DeleteObjectInfoIfNecessary(VarMap::iterator iter);
 
   VarMap live_vars_;
 
   // Last assigned var ID.
   int32 last_var_id_;
 
+ private:
+  // Create and return a new ArrayBufferVar size_in_bytes bytes long. This is
+  // implemented by the Host and Plugin tracker separately, so that it can be
+  // a real WebKit ArrayBuffer on the host side.
+  virtual ArrayBufferVar* CreateArrayBuffer(uint32 size_in_bytes) = 0;
+
   DISALLOW_COPY_AND_ASSIGN(VarTracker);
 };
 
 }  // namespace ppapi
 
 #endif  // PPAPI_SHARED_IMPL_VAR_TRACKER_H_