gpu: Add out-of-line copy ctors for complex classes.

gpu/command_buffer/service/program_manager.cc

Index: gpu/command_buffer/service/program_manager.cc
diff --git a/gpu/command_buffer/service/program_manager.cc b/gpu/command_buffer/service/program_manager.cc
index 257da8afb53d32314294d6375619f44ce08cdacf..91d49918edc7e4e21396ed57d68b9376df0fb13c 100644
--- a/gpu/command_buffer/service/program_manager.cc
+++ b/gpu/command_buffer/service/program_manager.cc
@@ -251,6 +251,9 @@ Program::UniformInfo::UniformInfo(const std::string& client_name,
   texture_units.clear();
   texture_units.resize(num_texture_units, 0);
 }
+
+Program::UniformInfo::UniformInfo(const UniformInfo& other) = default;
+
 Program::UniformInfo::~UniformInfo() {}
 
 bool ProgramManager::HasBuiltInPrefix(const std::string& name) {