Add test that attemps to translate a shader twice

gpu/command_buffer/service/shader_translator_unittest.cc

Index: gpu/command_buffer/service/shader_translator_unittest.cc
diff --git a/gpu/command_buffer/service/shader_translator_unittest.cc b/gpu/command_buffer/service/shader_translator_unittest.cc
index 7d797dce500aad588f8e20538ce5494f5294da06..3101f91eb714b63f233e53ca46476f85c2f2dc5c 100644
--- a/gpu/command_buffer/service/shader_translator_unittest.cc
+++ b/gpu/command_buffer/service/shader_translator_unittest.cc
@@ -417,6 +417,27 @@ TEST_F(ES3ShaderTranslatorTest, GetInterfaceBlocks) {
   EXPECT_TRUE(iter != interface_block_map.end());
 }
 
+TEST_F(ES3ShaderTranslatorTest, CompileTwice) {
+  const char* vs1 = "void main() { gl_Position = vec5(gl_DepthRange); }";
+
+  std::string info_log, translated_source;
+  int shader_version;
+  AttributeMap attrib_map;
+  UniformMap uniform_map;
+  VaryingMap varying_map;
+  InterfaceBlockMap interface_block_map;
+  OutputVariableList output_variable_list;
+  NameMap name_map;
+  vertex_translator_->Translate(
+      vs1, &info_log, &translated_source, &shader_version, &attrib_map,
+      &uniform_map, &varying_map, &interface_block_map, &output_variable_list,
+      &name_map);
+  vertex_translator_->Translate(
+      vs1, &info_log, &translated_source, &shader_version, &attrib_map,
+      &uniform_map, &varying_map, &interface_block_map, &output_variable_list,
+      &name_map);
+}
+
 TEST_F(ShaderTranslatorTest, OptionsString) {
   scoped_refptr<ShaderTranslator> translator_1 = new ShaderTranslator();
   scoped_refptr<ShaderTranslator> translator_2 = new ShaderTranslator();