diff --git a/ui/gl/gl_surface.cc b/ui/gl/gl_surface.cc
index 620cee7..4459d48 100644
--- a/ui/gl/gl_surface.cc
+++ b/ui/gl/gl_surface.cc
@@ -28,7 +28,7 @@ base::LazyInstance<base::ThreadLocalPointer<GLSurface> >::Leaky
 }  // namespace
 
 // static
-bool GLSurface::InitializeOneOff() {
+bool GLSurface::InitializeOneOff(GLImplementation impl) {
   DCHECK_EQ(kGLImplementationNone, GetGLImplementation());
 
   TRACE_EVENT0("gpu", "GLSurface::InitializeOneOff");
@@ -40,7 +40,8 @@ bool GLSurface::InitializeOneOff() {
   CommandLine* cmd = CommandLine::ForCurrentProcess();
 
   // The default implementation is always the first one in list.
-  GLImplementation impl = allowed_impls[0];
+  if (impl == kGLImplementationNone)
+    impl = allowed_impls[0];
   bool fallback_to_osmesa = false;
   if (cmd->HasSwitch(switches::kOverrideUseGLWithOSMesaForTests)) {
     impl = kGLImplementationOSMesaGL;
diff --git a/ui/gl/gl_surface.h b/ui/gl/gl_surface.h
index 54bcc37..d458063 100644
--- a/ui/gl/gl_surface.h
+++ b/ui/gl/gl_surface.h
@@ -72,7 +72,7 @@ class GL_EXPORT GLSurface : public base::RefCounted<GLSurface> {
   virtual bool PostSubBuffer(int x, int y, int width, int height);
 
   // Initialize GL bindings.
-  static bool InitializeOneOff();
+  static bool InitializeOneOff(GLImplementation = kGLImplementationNone);
 
   // Unit tests should call these instead of InitializeOneOff() to set up
   // GL bindings appropriate for tests.