Implement the Platform::sharedOffscreenGraphicsContext3D method.

webkit/gpu/webkit_gpu.gyp

Index: webkit/gpu/webkit_gpu.gyp
diff --git a/webkit/gpu/webkit_gpu.gyp b/webkit/gpu/webkit_gpu.gyp
new file mode 100644
index 0000000000000000000000000000000000000000..5db1fa7825ef54f341cea216a602260ecd348898
--- /dev/null
+++ b/webkit/gpu/webkit_gpu.gyp
@@ -0,0 +1,70 @@
+# Copyright (c) 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.
+
+{
+  'conditions': [
+    # TODO(stuartmorgan): All dependencies from code built on iOS to
+    # webkit/ should be removed, at which point this condition can be
+    # removed.
+    ['OS != "ios"', {
+      'variables': {
+        'conditions': [
+          ['inside_chromium_build==0', {
+            'webkit_src_dir': '../../../../..',
+          },{
+            'webkit_src_dir': '../../third_party/WebKit',
+          }],
+        ],
+      },
+      'targets': [
+        {
+          'target_name': 'webkit_gpu',
+          'type': '<(component)',
+          'variables': { 'enable_wexit_time_destructors': 1, },
+          'dependencies': [
+            '<(DEPTH)/base/base.gyp:base',
+            '<(DEPTH)/base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
+            '<(DEPTH)/gpu/command_buffer/command_buffer.gyp:gles2_utils',
+            '<(DEPTH)/gpu/gpu.gyp:command_buffer_service',
+            '<(DEPTH)/gpu/gpu.gyp:command_buffer_client',
+            '<(DEPTH)/gpu/gpu.gyp:gles2_c_lib',
+            '<(DEPTH)/gpu/gpu.gyp:gles2_implementation',
+            '<(DEPTH)/skia/skia.gyp:skia',
+            '<(DEPTH)/third_party/angle/src/build_angle.gyp:translator_glsl',
+            '<(DEPTH)/ui/gl/gl.gyp:gl',
+            '<(DEPTH)/ui/ui.gyp:ui',
+            '<(webkit_src_dir)/Source/WebKit/chromium/WebKit.gyp:webkit',
+          ],
+          'sources': [
+            # This list contains all .h and .cc in gpu except for test code.
+            'context_provider_in_process.cc',
+            'context_provider_in_process.h',
+            'gl_bindings_skia_cmd_buffer.cc',
+            'gl_bindings_skia_cmd_buffer.h',
+            'grcontext_for_webgraphicscontext3d.cc',
+            'grcontext_for_webgraphicscontext3d.h',
+            'test_context_provider_factory.cc',
+            'test_context_provider_factory.h',
+            'webgraphicscontext3d_in_process_command_buffer_impl.cc',
+            'webgraphicscontext3d_in_process_command_buffer_impl.h',
+            'webgraphicscontext3d_in_process_impl.cc',
+            'webgraphicscontext3d_in_process_impl.h',
+          ],
+          'conditions': [
+            ['inside_chromium_build==0', {
+              'dependencies': [
+                '<(DEPTH)/webkit/support/setup_third_party.gyp:third_party_headers',
+              ],
+            }],
+          ],
+          'defines': [
+            'WEBKIT_GPU_IMPLEMENTATION',
+          ],
+          # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+          'msvs_disabled_warnings': [ 4267, ],
+        },
+      ],
+    }],
+  ],
+}