Ensure GL initialization only happens once, and provide common init path

ui/gl/gl_surface_egl.cc

Index: ui/gl/gl_surface_egl.cc
diff --git a/ui/gl/gl_surface_egl.cc b/ui/gl/gl_surface_egl.cc
index 0db2fc72569c60ab0cbe27b0c22cca4ef6b88479..635595c7b998f7866d117f6bad17c1008e43585a 100644
--- a/ui/gl/gl_surface_egl.cc
+++ b/ui/gl/gl_surface_egl.cc
@@ -784,14 +784,14 @@ GLSurfaceOSMesaHeadless::~GLSurfaceOSMesaHeadless() { Destroy(); }
 
 // static
 bool GLSurface::InitializeOneOffInternal() {
-  if (GetGLImplementation() == kGLImplementationOSMesaGL) {
-    return true;
-  }
-  DCHECK(GetGLImplementation() == kGLImplementationEGLGLES2);
-
-  if (!GLSurfaceEGL::InitializeOneOff()) {
-    LOG(ERROR) << "GLSurfaceEGL::InitializeOneOff failed.";
-    return false;
+  switch (GetGLImplementation()) {
+    case kGLImplementationEGLGLES2:
+      if (!GLSurfaceEGL::InitializeOneOff()) {
+        LOG(ERROR) << "GLSurfaceEGL::InitializeOneOff failed.";
+        return false;
+      }
+    default:
+      break;
   }
   return true;
 }