[instrumentation] Introduce JSON5 config files for probe generator.

third_party/WebKit/Source/build/scripts/templates/InstrumentingProbesInl.h.tmpl

 // This file is generated from {{input_file}}
 
 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef {{file.header_name}}_h
 #define {{file.header_name}}_h
 
 #include "platform/heap/HeapAllocator.h"
 {% for include in file.includes %}
 {{include}}
 {% endfor %}
 
-{% for define in file.defines %}
-{{define}}
-{% endfor %}
+{% set export_symbol = config["settings"]["export_symbol"] %}
 
 namespace blink {
 
 {% for forward_decl in file.forward_declarations %}
 {{forward_decl}}
 {% endfor %}
 
 namespace probe {
 {% for probe in file.declarations %}
 
 {%- macro params_decl(probe) %}
 {%- for param in probe.params %}
 {{ param.type }}
 {%- if param.default_value %} = {{ param.default_value }}
 {%- endif %}
 {%- if not loop.last %}, {% endif %}
 {%- endfor %}
 {%- endmacro -%}
 
 {% if probe.is_scoped %}
 
 
-class PROBE_EXPORT {{probe.name}} : public ProbeBase {
+class {{export_symbol}} {{probe.name}} : public ProbeBase {
   STACK_ALLOCATED()
  public:
   explicit {{probe.name}}({{ params_decl(probe) }});
   ~{{probe.name}}();
 {% for param in probe.params %}
   {{param.member_type}} {{param.name}};
 {% endfor %}
 };
 {%- else %}
 
-PROBE_EXPORT {{probe.return_type}} {{probe.name}}({{ params_decl(probe) }});
+{{export_symbol}} {{probe.return_type}} {{probe.name}}({{ params_decl(probe) }});
 
 {%- endif %}
 {%- endfor %}
 
 
 } // namespace probe
 } // namespace blink
 
 #endif // !defined({{file.header_name}}_h)