Add support for GL_CHROMIUM_pixel_transfer_buffer_object.

content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc

Index: content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
diff --git a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
index 28ce7d3af30ae8f52719f8277aeb851f98fc40f2..be9f808c30e732c57a52a40dbed37a41857f2db3 100644
--- a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
+++ b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
@@ -1636,6 +1636,16 @@ DELEGATE_TO_GL_2(bindTexImage2DCHROMIUM, BindTexImage2DCHROMIUM,
 DELEGATE_TO_GL_2(releaseTexImage2DCHROMIUM, ReleaseTexImage2DCHROMIUM,
                  WGC3Denum, WGC3Dint)
 
+void* WebGraphicsContext3DCommandBufferImpl::mapBufferCHROMIUM(
+    WGC3Denum target, WGC3Denum access) {
+  return gl_->MapBufferCHROMIUM(target, access);
+}
+
+WGC3Dboolean WebGraphicsContext3DCommandBufferImpl::unmapBufferCHROMIUM(
+    WGC3Denum target) {
+  return gl_->UnmapBufferCHROMIUM(target);
+}
+
 GrGLInterface* WebGraphicsContext3DCommandBufferImpl::onCreateGrGLInterface() {
   return webkit_glue::CreateCommandBufferSkiaGLBinding();
 }