Mojo C++ bindings: support mapping mojo string to WTF::String.

mojo/mojom_bindings_generator_explicit.gypi

 # Copyright 2013 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.
 
 {
   'includes': [
     'mojom_bindings_generator_variables.gypi',
   ],
   'variables': {
     'variables': {
       'mojom_variant%': 'none',
+      'for_blink%': 'false',
     },
     'mojom_variant%': '<(mojom_variant)',
+    'for_blink%': '<(for_blink)',
     'mojom_base_output_dir':
         '<!(python <(DEPTH)/build/inverse_depth.py <(DEPTH))',
     'mojom_generated_outputs': [
       '<!@(python <(DEPTH)/mojo/public/tools/bindings/mojom_list_outputs.py --basedir <(mojom_base_output_dir) --variant <(mojom_variant) <@(mojom_files))',
     ],
     'mojom_include_path%': '<(DEPTH)',
     'mojom_extra_generator_args%': [],
     'require_interface_bindings%': 1,
     'conditions': [
       ['mojom_variant=="none"', {
         'mojom_output_languages%': 'c++,javascript,java',
       }, {
         'mojom_output_languages%': 'c++',
       }],
+      ['for_blink=="true"', {
+        'mojom_generator_wtf_arg%': [
+          '--for_blink',
+        ],
+        'wtf_dependencies%': [
+          'mojo_public.gyp:mojo_cpp_bindings_wtf_support',
+          '../third_party/WebKit/Source/wtf/wtf.gyp:wtf',
+        ],
+      }, {
+        'mojom_generator_wtf_arg%': [],
+        'wtf_dependencies%': [],
+      }],
     ],
   },
   # Given mojom files as inputs, generate sources.  These sources will be
   # exported to another target (via dependent_settings) to be compiled.  This
   # keeps code generation separate from compilation, allowing the same sources
   # to be compiled with multiple toolchains - target, NaCl, etc.
   'actions': [
     {
       'variables': {
         'java_out_dir': '<(PRODUCT_DIR)/java_mojo/<(_target_name)/src',
@@ skipping 38 matching lines @@
         'python', '<@(mojom_bindings_generator)',
         '--use_bundled_pylibs', 'generate',
         '<@(mojom_files)',
         '-d', '<(DEPTH)',
         '<@(mojom_import_args)',
         '-o', '<(SHARED_INTERMEDIATE_DIR)',
         '--java_output_directory=<(java_out_dir)',
         '--variant', '<(mojom_variant)',
         '-g', '<(mojom_output_languages)',
         '<@(mojom_extra_generator_args)',
+        '<@(mojom_generator_wtf_arg)',
         '--bytecode_path',
         '<(SHARED_INTERMEDIATE_DIR)/mojo/public/tools/bindings',
       ],
       'message': 'Generating Mojo bindings from <@(mojom_files)',
     }
   ],
   'conditions': [
     ['require_interface_bindings==1', {
       'dependencies': [
         '<(DEPTH)/base/base.gyp:base',
         '<(DEPTH)/mojo/mojo_public.gyp:mojo_interface_bindings_generation',
       ],
     }],
   ],
   'dependencies': [
     '<(DEPTH)/mojo/public/tools/bindings/bindings.gyp:precompile_mojom_bindings_generator_templates',
+    '<@(wtf_dependencies)',
+  ],
+  'export_dependent_settings': [
+    '<@(wtf_dependencies)',
   ],
   # Prevent the generated sources from being injected into the "all" target by
   # preventing the code generator from being directly depended on by the "all"
   # target.
   'suppress_wildcard': '1',
   'hard_dependency': '1',
   'direct_dependent_settings': {
     # A target directly depending on this action will compile the generated
     # sources.
     'sources': [
@@ skipping 20 matching lines @@
         ],
         'additional_input_paths': [
           '<@(mojom_bindings_generator_sources)',
           '<@(mojom_files)',
         ],
         'mojom_generated_sources': [ '<@(mojom_generated_outputs)' ],
       },
     }
   },
 }