Revert 95611 - Always call the class methods to save/restore contexts.

ui/gfx/scoped_ns_graphics_context_save_gstate_mac.mm

Index: ui/gfx/scoped_ns_graphics_context_save_gstate_mac.mm
===================================================================
--- ui/gfx/scoped_ns_graphics_context_save_gstate_mac.mm	(revision 95630)
+++ ui/gfx/scoped_ns_graphics_context_save_gstate_mac.mm	(working copy)
@@ -4,20 +4,19 @@
 
 #include "ui/gfx/scoped_ns_graphics_context_save_gstate_mac.h"
 
-#import <AppKit/AppKit.h>
+#include <AppKit/AppKit.h>
 
-#include "base/logging.h"
-
 namespace gfx {
 
-ScopedNSGraphicsContextSaveGState::ScopedNSGraphicsContextSaveGState()
-    : context_([NSGraphicsContext currentContext]) {
-  [NSGraphicsContext saveGraphicsState];
+ScopedNSGraphicsContextSaveGState::ScopedNSGraphicsContextSaveGState(
+    NSGraphicsContext* context) : context_([context retain]) {
+  if (!context_)
+    context_.reset([[NSGraphicsContext currentContext] retain]);
+  [context_ saveGraphicsState];
 }
 
 ScopedNSGraphicsContextSaveGState::~ScopedNSGraphicsContextSaveGState() {
-  [NSGraphicsContext restoreGraphicsState];
-  DCHECK_EQ(context_, [NSGraphicsContext currentContext]);
+  [context_ restoreGraphicsState];
 }
 
 }  // namespace gfx