Replace NPObject usage in ppapi with gin

content/renderer/pepper/pepper_plugin_instance_impl.h

Index: content/renderer/pepper/pepper_plugin_instance_impl.h
diff --git a/content/renderer/pepper/pepper_plugin_instance_impl.h b/content/renderer/pepper/pepper_plugin_instance_impl.h
index 4b86e6e67c2eb6af8a76fbc077e6ba8be9674188..b02d3cb6f7d143a40013f3b5ca31e6edaeb96538 100644
--- a/content/renderer/pepper/pepper_plugin_instance_impl.h
+++ b/content/renderer/pepper/pepper_plugin_instance_impl.h
@@ -23,6 +23,7 @@
 #include "content/public/renderer/pepper_plugin_instance.h"
 #include "content/public/renderer/render_frame_observer.h"
 #include "content/renderer/mouse_lock_dispatcher.h"
+#include "gin/handle.h"
 #include "ppapi/c/dev/pp_cursor_type_dev.h"
 #include "ppapi/c/dev/ppp_printing_dev.h"
 #include "ppapi/c/dev/ppp_selection_dev.h"
@@ -131,7 +132,6 @@ class CONTENT_EXPORT PepperPluginInstanceImpl
                                           const GURL& plugin_url);
   RenderFrameImpl* render_frame() const { return render_frame_; }
   PluginModule* module() const { return module_.get(); }
-  MessageChannel& message_channel() { return *message_channel_; }
 
   blink::WebPluginContainer* container() const { return container_; }
 
@@ -143,6 +143,10 @@ class CONTENT_EXPORT PepperPluginInstanceImpl
     return *resource_creation_.get();
   }
 
+  // This pointer is only valid on the stack.

[dmichael (off chromium), 2014/08/21 22:24:25]

The way I'm reading it, it makes a HandleScope that goes out of scope before
returning. So the pointer is only valid because of the Persistent handle, I
think. So the comment is misleading IMO.

[raymes, 2014/08/22 08:28:40]

The reason is because the underlying v8 object could get destroyed at any point
in time, so you wouldn't want to store the pointer somewhere unless you knew
what you were doing. Does that make sense? Let me know if I can make the comment
more clear.

[dmichael (off chromium), 2014/08/25 17:31:11]

I guess my point is that the lifetime issue has nothing to do with whether the
pointer is on the stack. A comment is fine, but it would be better to say
something like...
"This pointer is only valid while the PepperPluginInstanceImpl is valid."
(AIUI, the v8 object can't get destroyed at any point... because
PepperPluginInstanceImpl pins it in memory via a Persistent handle)

[raymes, 2014/08/26 05:15:11]

I agree. I removed that comment and I added a comment above the message_channel_
member in the last patch set :)

+  MessageChannel* GetMessageChannel();
+  v8::Local<v8::Object> GetMessageChannelObject();
+
   // Return the v8 context that the plugin is in.
   v8::Local<v8::Context> GetContext();
 
@@ -189,7 +193,7 @@ class CONTENT_EXPORT PepperPluginInstanceImpl
   bool HandleDocumentLoad(const blink::WebURLResponse& response);
   bool HandleInputEvent(const blink::WebInputEvent& event,
                         blink::WebCursorInfo* cursor_info);
-  PP_Var GetInstanceObject();
+  PP_Var GetInstanceObject(v8::Isolate* isolate);
   void ViewChanged(const gfx::Rect& position,
                    const gfx::Rect& clip,
                    const std::vector<gfx::Rect>& cut_outs_rects);
@@ -518,10 +522,6 @@ class CONTENT_EXPORT PepperPluginInstanceImpl
   // the given module.
   bool IsValidInstanceOf(PluginModule* module);
 
-  // Returns the plugin NPP identifier that this plugin will use to identify
-  // itself when making NPObject scripting calls to WebBindings.
-  struct _NPP* instanceNPP();
-
   // cc::TextureLayerClient implementation.
   virtual bool PrepareTextureMailbox(
       cc::TextureMailbox* mailbox,
@@ -830,7 +830,7 @@ class CONTENT_EXPORT PepperPluginInstanceImpl
 
   // The MessageChannel used to implement bidirectional postMessage for the
   // instance.
-  scoped_ptr<MessageChannel> message_channel_;
+  v8::Persistent<v8::Object> message_channel_;
 
   // Bitmap for crashed plugin. Lazily initialized, non-owning pointer.
   SkBitmap* sad_plugin_;
@@ -880,10 +880,6 @@ class CONTENT_EXPORT PepperPluginInstanceImpl
   // The link currently under the cursor.
   base::string16 link_under_cursor_;
 
-  // Dummy NPP value used when calling in to WebBindings, to allow the bindings
-  // to correctly track NPObjects belonging to this plugin instance.
-  scoped_ptr<struct _NPP> npp_;
-
   // We store the isolate at construction so that we can be sure to use the
   // Isolate in which this Instance was created when interacting with v8.
   v8::Isolate* isolate_;