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

gpu/command_buffer/service/gles2_cmd_decoder_unittest_base.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder_unittest_base.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_unittest_base.cc b/gpu/command_buffer/service/gles2_cmd_decoder_unittest_base.cc
index 8b6d24a61e1845411739a25fb7488c468ae9d671..1b2484ba021f23deeeed3593ea67149ee38b5362 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_unittest_base.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_unittest_base.cc
@@ -166,6 +166,8 @@ GLES2DecoderTestBase::InitState::InitState()
       use_native_vao(true),
       context_type(CONTEXT_TYPE_OPENGLES2) {}
 
+GLES2DecoderTestBase::InitState::InitState(const InitState& other) = default;
+
 void GLES2DecoderTestBase::InitDecoder(const InitState& init) {
   InitDecoderWithCommandLine(init, NULL);
 }