Add VTSupport for dynamically linking VideoToolbox.

content/content_common.gypi

Index: content/content_common.gypi
diff --git a/content/content_common.gypi b/content/content_common.gypi
index 240c001fccac7199cc5122b955c23b68778df593..1b0ad172fee911c4c8ff83168597d4536892eb61 100644
--- a/content/content_common.gypi
+++ b/content/content_common.gypi
@@ -581,6 +581,45 @@
           '$(SDKROOT)/System/Library/Frameworks/QuartzCore.framework',
         ],
       },
+      'variables': {
+        'generate_stubs_script': '../tools/generate_stubs/generate_stubs.py',
+        'extra_header': 'common/gpu/media/vt_stubs_header.fragment',
+        'sig_files': ['common/gpu/media/vt.sig'],
+        'outfile_type': 'posix_stubs',
+        'stubs_filename_root': 'vt_stubs',
+        'project_path': 'content/common/gpu/media',
+        'intermediate_dir': '<(INTERMEDIATE_DIR)',
+        'output_root': '<(SHARED_INTERMEDIATE_DIR)/vt_stubs',
+      },
+      'include_dirs': [
+        '<(output_root)',
+      ],
+      'actions': [
+        {
+          'action_name': 'generate_stubs',
+          'inputs': [
+            '<(generate_stubs_script)',
+            '<(extra_header)',
+            '<@(sig_files)',
+          ],
+          'outputs': [
+            '<(intermediate_dir)/<(stubs_filename_root).cc',
+            '<(output_root)/<(project_path)/<(stubs_filename_root).h',
+          ],
+          'action': ['python',
+                     '<(generate_stubs_script)',
+                     '-i', '<(intermediate_dir)',
+                     '-o', '<(output_root)/<(project_path)',
+                     '-t', '<(outfile_type)',
+                     '-e', '<(extra_header)',
+                     '-s', '<(stubs_filename_root)',
+                     '-p', '<(project_path)',
+                     '<@(_inputs)',
+          ],
+          'process_outputs_as_sources': 1,
+          'message': 'Generating VideoToolbox stubs for dynamic loading',
+        },
+      ],
     }],
     ['OS=="android"',{
       'sources': [