PPAPI: Refactor renderer side of browser host creation

content/renderer/pepper/resource_converter.cc

Index: content/renderer/pepper/resource_converter.cc
diff --git a/content/renderer/pepper/resource_converter.cc b/content/renderer/pepper/resource_converter.cc
index 2af3bba3e7799d5864281bc05397c88e052477e3..f4d639f1e68c316aa7e775a947b386303a5a2f8f 100644
--- a/content/renderer/pepper/resource_converter.cc
+++ b/content/renderer/pepper/resource_converter.cc
@@ -5,6 +5,7 @@
 #include "content/renderer/pepper/resource_converter.h"
 
 #include "base/bind.h"
+#include "base/callback.h"
 #include "base/message_loop/message_loop.h"
 #include "content/public/renderer/renderer_ppapi_host.h"
 #include "content/renderer/pepper/pepper_file_system_host.h"
@@ -29,17 +30,6 @@ using ppapi::ResourceVar;
 namespace content {
 namespace {
 
-void FlushComplete(
-    const base::Callback<void(bool)>& callback,
-    const std::vector<scoped_refptr<content::HostResourceVar> >& browser_vars,
-    const std::vector<int>& pending_host_ids) {
-  CHECK(browser_vars.size() == pending_host_ids.size());
-  for (size_t i = 0; i < browser_vars.size(); ++i) {
-    browser_vars[i]->set_pending_browser_host_id(pending_host_ids[i]);
-  }
-  callback.Run(true);
-}
-
 // Converts a blink::WebFileSystem::Type to a PP_FileSystemType.
 PP_FileSystemType WebFileSystemTypeToPPAPI(blink::WebFileSystem::Type type) {
   switch (type) {
@@ -198,7 +188,8 @@ bool DOMMediaStreamTrackToResource(
 ResourceConverter::~ResourceConverter() {}
 
 ResourceConverterImpl::ResourceConverterImpl(PP_Instance instance)
-    : instance_(instance) {}
+    : instance_(instance), weak_ptr_factory_(this) {
+}
 
 ResourceConverterImpl::~ResourceConverterImpl() {
   // Verify Flush() was called.
@@ -276,12 +267,17 @@ bool ResourceConverterImpl::NeedsFlush() {
 }
 
 void ResourceConverterImpl::Flush(const base::Callback<void(bool)>& callback) {
-  RendererPpapiHost::GetForPPInstance(instance_)->CreateBrowserResourceHosts(
-      instance_,
-      browser_host_create_messages_,
-      base::Bind(&FlushComplete, callback, browser_vars_));
+  pending_conversions_.push(PendingConversion());
+  pending_conversions_.back().callback = callback;
+  pending_conversions_.back().browser_vars.swap(browser_vars_);
+  pending_conversions_.back().sequence_number =
+      RendererPpapiHost::GetForPPInstance(instance_)
+          ->CreateBrowserResourceHosts(
+              instance_, browser_host_create_messages_,
+              base::Bind(&ResourceConverterImpl::FlushComplete,
+                         weak_ptr_factory_.GetWeakPtr()));
+
   browser_host_create_messages_.clear();
-  browser_vars_.clear();
 }
 
 bool ResourceConverterImpl::ToV8Value(const PP_Var& var,
@@ -332,6 +328,11 @@ bool ResourceConverterImpl::ToV8Value(const PP_Var& var,
   }
 }
 
+ResourceConverterImpl::PendingConversion::PendingConversion() {
+}
+ResourceConverterImpl::PendingConversion::~PendingConversion() {
+}
+
 scoped_refptr<HostResourceVar> ResourceConverterImpl::CreateResourceVar(
     int pending_renderer_id,
     const IPC::Message& create_message) {
@@ -350,4 +351,24 @@ ResourceConverterImpl::CreateResourceVarWithBrowserHost(
   return result;
 }
 
+void ResourceConverterImpl::FlushComplete(
+    const ppapi::proxy::CompletedBrowserResourceHosts& hosts) {
+  if (pending_conversions_.empty() ||
+      hosts.sequence_number != pending_conversions_.front().sequence_number) {
+    NOTREACHED();
+    return;
+  }
+  const PendingConversion& conversion = pending_conversions_.front();
+  if (conversion.browser_vars.size() != hosts.host_ids.size()) {
+    NOTREACHED();
+    pending_conversions_.pop();
+    return;
+  }
+  for (size_t i = 0; i < conversion.browser_vars.size(); ++i) {
+    conversion.browser_vars[i]->set_pending_browser_host_id(hosts.host_ids[i]);
+  }
+  conversion.callback.Run(true);
+  pending_conversions_.pop();
+}
+
 }  // namespace content