Revert of Replace NPObject usage in ppapi with gin

content/renderer/pepper/host_var_tracker.h

Index: content/renderer/pepper/host_var_tracker.h
diff --git a/content/renderer/pepper/host_var_tracker.h b/content/renderer/pepper/host_var_tracker.h
index a5518c8033805904a182d9001353a0540ee654ea..8d8176a7c6eb2846b6000451b89dfa4b2d3b0940 100644
--- a/content/renderer/pepper/host_var_tracker.h
+++ b/content/renderer/pepper/host_var_tracker.h
@@ -20,30 +20,52 @@
 #include "ppapi/shared_impl/var_tracker.h"
 #include "v8/include/v8.h"
 
+typedef struct NPObject NPObject;
+
 namespace ppapi {
 class ArrayBufferVar;
+class NPObjectVar;
 class V8ObjectVar;
 class Var;
 }
 
 namespace content {
 
+// Adds NPObject var tracking to the standard PPAPI VarTracker for use in the
+// renderer.
 class HostVarTracker : public ppapi::VarTracker {
  public:
   HostVarTracker();
   virtual ~HostVarTracker();
 
+  // Tracks all live NPObjectVar. This is so we can map between instance +
+  // NPObject and get the NPObjectVar corresponding to it. This Add/Remove
+  // function is called by the NPObjectVar when it is created and
+  // destroyed.
+  void AddNPObjectVar(ppapi::NPObjectVar* object_var);
+  void RemoveNPObjectVar(ppapi::NPObjectVar* object_var);
+
+  // Looks up a previously registered NPObjectVar for the given NPObject and
+  // instance. Returns NULL if there is no NPObjectVar corresponding to the
+  // given NPObject for the given instance. See AddNPObjectVar above.
+  ppapi::NPObjectVar* NPObjectVarForNPObject(PP_Instance instance,
+                                             NPObject* np_object);
+
+  // Returns the number of NPObjectVar's associated with the given instance.
+  // Returns 0 if the instance isn't known.
+  CONTENT_EXPORT int GetLiveNPObjectVarsForInstance(PP_Instance instance) const;
+
   // Tracks all live V8ObjectVar. This is so we can map between instance +
   // V8Object and get the V8ObjectVar corresponding to it. This Add/Remove
   // function is called by the V8ObjectVar when it is created and destroyed.
-  void AddV8ObjectVar(ppapi::V8ObjectVar* object_var);
-  void RemoveV8ObjectVar(ppapi::V8ObjectVar* object_var);
+  void AddV8ObjectVar(ppapi::V8ObjectVar* object_var) { NOTIMPLEMENTED(); }
+  void RemoveV8ObjectVar(ppapi::V8ObjectVar* object_var) { NOTIMPLEMENTED(); }
   // Creates or retrieves a V8ObjectVar.
   PP_Var V8ObjectVarForV8Object(PP_Instance instance,
-                                v8::Handle<v8::Object> object);
-  // Returns the number of V8ObjectVars associated with the given instance.
-  // Returns 0 if the instance isn't known.
-  CONTENT_EXPORT int GetLiveV8ObjectVarsForTest(PP_Instance instance);
+                                v8::Handle<v8::Object> object) {
+    NOTIMPLEMENTED();
+    return PP_MakeUndefined();
+  }
 
   // VarTracker public implementation.
   virtual PP_Var MakeResourcePPVarFromMessage(
@@ -52,7 +74,7 @@
       int pending_renderer_id,
       int pending_browser_id) OVERRIDE;
   virtual ppapi::ResourceVar* MakeResourceVar(PP_Resource pp_resource) OVERRIDE;
-  virtual void DidDeleteInstance(PP_Instance pp_instance) OVERRIDE;
+  virtual void DidDeleteInstance(PP_Instance instance) OVERRIDE;
 
   virtual int TrackSharedMemoryHandle(PP_Instance instance,
                                       base::SharedMemoryHandle file,
@@ -72,30 +94,20 @@
 
   // Clear the reference count of the given object and remove it from
   // live_vars_.
-  void ForceReleaseV8Object(ppapi::V8ObjectVar* object_var);
+  void ForceReleaseNPObject(ppapi::NPObjectVar* object_var);
 
-  // A non-unique, ordered key for a V8ObjectVar. Contains the hash of the v8
-  // and the instance it is associated with.
-  struct V8ObjectVarKey {
-    explicit V8ObjectVarKey(ppapi::V8ObjectVar* object_var);
-    V8ObjectVarKey(PP_Instance i, v8::Handle<v8::Object> object);
-    ~V8ObjectVarKey();
+  typedef std::map<NPObject*, ppapi::NPObjectVar*> NPObjectToNPObjectVarMap;
 
-    bool operator<(const V8ObjectVarKey& other) const;
-
-    PP_Instance instance;
-    int hash;
-  };
-  typedef std::multimap<V8ObjectVarKey, ppapi::V8ObjectVar*> ObjectMap;
-
-  // Returns an iterator into |object_map| which points to V8Object which
-  // is associated with the given instance and object.
-  ObjectMap::iterator GetForV8Object(PP_Instance instance,
-                                     v8::Handle<v8::Object> object);
-
-
-  // A multimap of V8ObjectVarKey -> ObjectMap.
-  ObjectMap object_map_;
+  // Lists all known NPObjects, first indexed by the corresponding instance,
+  // then by the NPObject*. This allows us to look up an NPObjectVar given
+  // these two pieces of information.
+  //
+  // The instance map is lazily managed, so we'll add the
+  // NPObjectToNPObjectVarMap lazily when the first NPObject var is created,
+  // and delete it when it's empty.
+  typedef std::map<PP_Instance, linked_ptr<NPObjectToNPObjectVarMap> >
+      InstanceMap;
+  InstanceMap instance_map_;
 
   // Tracks all shared memory handles used for transmitting array buffers.
   struct SharedMemoryMapEntry {