PPAPI: Support sending browser-hosted resources synchronously

content/renderer/pepper/resource_converter.h

 // Copyright 2013 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 CONTENT_RENDERER_PEPPER_RESOURCE_CONVERTER_H
 #define CONTENT_RENDERER_PEPPER_RESOURCE_CONVERTER_H
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "content/common/content_export.h"
 #include "content/renderer/pepper/host_resource_var.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/pp_var.h"
 #include "v8/include/v8.h"
 
 namespace IPC {
 class Message;
 }
 
 namespace ppapi {
+
 class ScopedPPVar;
+
+namespace proxy {
+struct CompletedBrowserResourceHosts;
 }
 
+}  // namespace ppapi
+
 namespace content {
 
 // This class is responsible for converting V8 vars to Pepper resources.
 class CONTENT_EXPORT ResourceConverter {
  public:
   virtual ~ResourceConverter();
 
   // Reset the state of the resource converter.
   virtual void Reset() = 0;
 
   // Returns true if Flush() needs to be called before using any vars created
   // by the resource converter.
   virtual bool NeedsFlush() = 0;
 
   // If NeedsFlush() is true then Flush() must be called before any vars created
   // by the ResourceConverter are valid. It handles creating any resource hosts
   // that need to be created. |callback| will always be called asynchronously.
   virtual void Flush(const base::Callback<void(bool)>& callback) = 0;
+  // Flush, but don't return until the resource hosts are all created, including
+  // in the browser side.
+  virtual void FlushSync() = 0;
 
   // Attempts to convert a V8 object to a PP_Var with type PP_VARTYPE_RESOURCE.
   // On success, writes the resulting var to |result|, sets |was_resource| to
   // true and returns true. If |val| is not a resource, sets |was_resource| to
   // false and returns true. If an error occurs, returns false.
   virtual bool FromV8Value(v8::Handle<v8::Object> val,
                            v8::Handle<v8::Context> context,
                            PP_Var* result,
                            bool* was_resource) = 0;
 
   // Attempts to convert a PP_Var to a V8 object. |var| must have type
   // PP_VARTYPE_RESOURCE. On success, writes the resulting value to |result| and
   // returns true. If an error occurs, returns false.
   virtual bool ToV8Value(const PP_Var& var,
                          v8::Handle<v8::Context> context,
                          v8::Handle<v8::Value>* result) = 0;
 };
 
 class ResourceConverterImpl : public ResourceConverter {
  public:
   explicit ResourceConverterImpl(PP_Instance instance);
   ~ResourceConverterImpl() override;
 
   // ResourceConverter overrides.
   void Reset() override;
   bool NeedsFlush() override;
   void Flush(const base::Callback<void(bool)>& callback) override;
+  void FlushSync() override;
   bool FromV8Value(v8::Handle<v8::Object> val,
                    v8::Handle<v8::Context> context,
                    PP_Var* result,
                    bool* was_resource) override;
   bool ToV8Value(const PP_Var& var,
                  v8::Handle<v8::Context> context,
                  v8::Handle<v8::Value>* result) override;
 
  private:
+  // A list of the resource vars associated with browser hosts.
+  typedef std::vector<scoped_refptr<HostResourceVar>> VarVector;
+
+  struct PendingConversion {
+    PendingConversion();
+    ~PendingConversion();
+    int sequence_num;
+    base::Callback<void(bool)> callback;
+    VarVector browser_vars;
+  };
+
   // Creates a resource var with the given |pending_renderer_id| and
   // |create_message| to be sent to the plugin.
   scoped_refptr<HostResourceVar> CreateResourceVar(
       int pending_renderer_id,
       const IPC::Message& create_message);
   // Creates a resource var with the given |pending_renderer_id| and
   // |create_message| to be sent to the plugin. Also sends
   // |browser_host_create_message| to the browser, and asynchronously stores the
   // resulting browser host ID in the newly created var.
   scoped_refptr<HostResourceVar> CreateResourceVarWithBrowserHost(
       int pending_renderer_id,
       const IPC::Message& create_message,
       const IPC::Message& browser_host_create_message);
 
+  void FlushComplete(const ppapi::proxy::CompletedBrowserResourceHosts& hosts);
+
   // The instance this ResourceConverter is associated with.
   PP_Instance instance_;
 
   // A list of the messages to create the browser hosts. This is a parallel
   // array to |browser_vars|. It is kept as a parallel array so that it can be
   // conveniently passed to |CreateBrowserResourceHosts|.
   std::vector<IPC::Message> browser_host_create_messages_;
-  // A list of the resource vars associated with browser hosts.
-  std::vector<scoped_refptr<HostResourceVar> > browser_vars_;
+  VarVector browser_vars_;
+
+  std::queue<PendingConversion> pending_conversions_;
+
+  base::WeakPtrFactory<ResourceConverterImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceConverterImpl);
 };
 
 }  // namespace content
 #endif  // CONTENT_RENDERER_PEPPER_RESOURCE_CONVERTER_H