Revert "Remove the enable-d3d11 flag so that d3d11 is enabled by default."

ui/gl/gl_switches.cc

Index: ui/gl/gl_switches.cc
diff --git a/ui/gl/gl_switches.cc b/ui/gl/gl_switches.cc
index d32786fd43c0be436455d38fb8488e93427ece38..fb9d3d8543f24f364a6f1483a67b855cf6082ae3 100644
--- a/ui/gl/gl_switches.cc
+++ b/ui/gl/gl_switches.cc
@@ -18,6 +18,9 @@ const char kGLImplementationMockName[]        = "mock";
 
 namespace switches {
 
+// Enables use of D3D11 when available.
+const char kEnableD3D11[]                   = "enable-d3d11";
+
 // Disables use of D3D11.
 const char kDisableD3D11[]                  = "disable-d3d11";
 
@@ -72,6 +75,7 @@ const char kUseGpuInTests[] = "use-gpu-in-tests";
 // to read it in the GPU process, else don't add it.
 const char* kGLSwitchesCopiedFromGpuProcessHost[] = {
   kDisableGpuVsync,
+  kEnableD3D11,
   kDisableD3D11,
   kEnableGPUServiceLogging,
   kEnableGPUServiceTracing,