PPAPI: Support sending browser-hosted resources synchronously

content/renderer/pepper/resource_converter.h

Index: content/renderer/pepper/resource_converter.h
diff --git a/content/renderer/pepper/resource_converter.h b/content/renderer/pepper/resource_converter.h
index d669e7464b4ad094dc4fb0eb3eea10bc0e92c990..70b92535ded0aa1716b29b2e5980577505e3d0f0 100644
--- a/content/renderer/pepper/resource_converter.h
+++ b/content/renderer/pepper/resource_converter.h
@@ -11,6 +11,7 @@
 #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"
@@ -22,9 +23,15 @@ 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.
@@ -43,6 +50,9 @@ class CONTENT_EXPORT ResourceConverter {
   // 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
@@ -70,6 +80,7 @@ class ResourceConverterImpl : public ResourceConverter {
   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,
@@ -79,6 +90,17 @@ class ResourceConverterImpl : public ResourceConverter {
                  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(
@@ -93,6 +115,8 @@ class ResourceConverterImpl : public ResourceConverter {
       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_;
 
@@ -100,8 +124,11 @@ class ResourceConverterImpl : public ResourceConverter {
   // 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);
 };