Switch all contexts in a share group to be on the same screen as the window they present to.

ui/gl/gl_share_group.cc

Index: ui/gl/gl_share_group.cc
diff --git a/ui/gl/gl_share_group.cc b/ui/gl/gl_share_group.cc
index 34f7c7f2f14c0248fa9c2d86bc9882588056eb8f..8e8958b49a42179c15d2b96811e6006a96554dac 100644
--- a/ui/gl/gl_share_group.cc
+++ b/ui/gl/gl_share_group.cc
@@ -10,7 +10,11 @@
 namespace gfx {
 
 GLShareGroup::GLShareGroup()
-    : shared_context_(NULL) {
+    : shared_context_(NULL)
+#if defined(OS_MACOSX)
+    , renderer_id_(-1)
+#endif
+    {
 }
 
 void GLShareGroup::AddContext(GLContext* context) {
@@ -51,6 +55,16 @@ GLContext* GLShareGroup::GetSharedContext() {
   return shared_context_;
 }
 
+#if defined(OS_MACOSX)
+void GLShareGroup::SetRendererID(int renderer_id) {
+  renderer_id_ = renderer_id;
+}
+
+int GLShareGroup::GetRendererID() {
+  return renderer_id_;
+}
+#endif
+
 GLShareGroup::~GLShareGroup() {
 }