Add gl tests to make sure when a buffer is unmapped, all access path generates an INVALID_OPERATION.

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 754d5b0630b16d7d450787076dbbfbfd6b3fb257..a83ac5c518459166178efdcd6e00c3c11fdd7bbd 100644
--- a/gpu/command_buffer/service/program_manager.cc
+++ b/gpu/command_buffer/service/program_manager.cc
@@ -338,6 +338,7 @@ Program::Program(ProgramManager* manager, GLuint service_id)
       link_status_(false),
       uniforms_cleared_(false),
       transform_feedback_buffer_mode_(GL_NONE),
+      effective_transform_feedback_buffer_mode_(GL_NONE),
       fragment_output_type_mask_(0u),
       fragment_output_written_mask_(0u) {
   DCHECK(manager_);
@@ -693,6 +694,9 @@ void Program::Update() {
   UpdateVertexInputBaseTypes();
   UpdateUniformBlockSizeInfo();
 
+  effective_transform_feedback_buffer_mode_ = transform_feedback_buffer_mode_;
+  effective_transform_feedback_varyings_ = transform_feedback_varyings_;
+
   valid_ = true;
 }
 
@@ -1325,8 +1329,8 @@ bool Program::Link(ShaderManager* manager,
                                  attached_shaders_[0].get(),
                                  attached_shaders_[1].get(),
                                  &bind_attrib_location_map_,
-                                 transform_feedback_varyings_,
-                                 transform_feedback_buffer_mode_,
+                                 effective_transform_feedback_varyings_,
+                                 effective_transform_feedback_buffer_mode_,
                                  shader_callback);
       }
       UMA_HISTOGRAM_CUSTOM_COUNTS(