From 1931db04cf4b3737adfb99edf86cbf68d740511b Mon Sep 17 00:00:00 2001
From: Jose Dapena Paz <jdapena@igalia.com>
Date: Thu, 20 Feb 2020 11:41:29 +0100
Subject: [PATCH] GNU stdc++: media::MediaError default constructor should be public

On building with GNU stdc++ we get this error building:
  gen/media/mojo/mojom/media_types.mojom.cc:1161:55:   required from here
  /usr/include/c++/9/bits/stl_construct.h:75:7: error: ‘media::MediaError::MediaError()’ is private within this context

This is because the serialization code will eventually call, in this case,
the default constructor because of the implementation of stl_uninitialized
that is used to create an std::vector. This is invoked from
static bool mojo::ArrayTraits<std::vector<_Tp> >::Resize(std::vector<_Tp>&, size_t)
and what it does is constructing a temporary vector like this:
    std::vector<T> temp(size);

But this is requiring calling the default constructor of T (in this case
MediaError) for all the elements up to size-1.

Bug: 957519
Change-Id: Ie3a28b9734f16c5155b9500003838510be0a748d
---

diff --git a/media/base/media_error.h b/media/base/media_error.h
index d3ba96c..56daaec 100644
--- a/media/base/media_error.h
+++ b/media/base/media_error.h
@@ -40,6 +40,9 @@
 // successful returns.
 class MEDIA_EXPORT MediaError {
  public:
+  // Default constructor can be used for MediaError::Ok();
+  MediaError();
+
   // Convenience function to return |kOk|.
   // OK won't have a message, trace, or data associated with them, and DCHECK
   // if they are added.
@@ -110,9 +113,6 @@
   }
 
  private:
-  // Default constructor can be used for MediaError::Ok();
-  MediaError();
-
   // Private helper to add the current stack frame to the error trace.
   void AddFrame(const base::Location& location);