Change the cpp wrappers of audio input/video capture to use CompletionCallbackWithOutput.

ppapi/cpp/array_output.cc

Index: ppapi/cpp/array_output.cc
diff --git a/ppapi/cpp/array_output.cc b/ppapi/cpp/array_output.cc
index 4cb8c857b23b0184363422eea3d9d67fd4175531..62252f72562d5d4bd5fc3cbc06b2d861ac72ccce 100644
--- a/ppapi/cpp/array_output.cc
+++ b/ppapi/cpp/array_output.cc
@@ -21,6 +21,13 @@ VarArrayOutputAdapterWithStorage::VarArrayOutputAdapterWithStorage()
   set_output(&temp_storage_);
 }
 
+VarArrayOutputAdapterWithStorage::~VarArrayOutputAdapterWithStorage() {
+  if (!temp_storage_.empty()) {
+    // An easy way to release the var references held by this object.
+    output();
+  }
+}
+
 std::vector<Var>& VarArrayOutputAdapterWithStorage::output() {
   PP_DCHECK(output_storage_.empty());