Always call the class methods to save/restore contexts.

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_toolbar_view.mm

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_bar_toolbar_view.h"
 
 #include "chrome/browser/ntp_background_util.h"
 #include "chrome/browser/themes/theme_service.h"
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_bar_constants.h"
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_bar_controller.h"
@@ skipping 38 matching lines @@
   // The state of our morph; 1 is total bubble, 0 is the regular bar. We use it
   // to morph the bubble to a regular bar (shape and colour).
   CGFloat morph = [controller_ detachedMorphProgress];
 
   NSRect bounds = [self bounds];
 
   ui::ThemeProvider* themeProvider = [controller_ themeProvider];
   if (!themeProvider)
     return;
 
-  NSGraphicsContext* context = [NSGraphicsContext currentContext];
-  gfx::ScopedNSGraphicsContextSaveGState scopedGState(context);
+  gfx::ScopedNSGraphicsContextSaveGState scopedGState;
 
   // Draw the background.
   {
     // CanvasSkiaPaint draws to the NSGraphicsContext during its destructor, so
     // explicitly scope this.
     //
     // Paint the entire bookmark bar, even if the damage rect is much smaller
     // because PaintBackgroundDetachedMode() assumes that area's origin is
     // (0, 0) and that its size is the size of the bookmark bar.
     //
@@ skipping 25 matching lines @@
 
   // Draw the rounded rectangle.
   NSColor* toolbarColor =
       themeProvider->GetNSColor(ThemeService::COLOR_TOOLBAR, true);
   CGFloat alpha = morph * [toolbarColor alphaComponent];
   [[toolbarColor colorWithAlphaComponent:alpha] set];  // Set with opacity.
   [border fill];
 
   // Fade in/out the background.
   {
-    gfx::ScopedNSGraphicsContextSaveGState bgScopedState(context);
+    gfx::ScopedNSGraphicsContextSaveGState bgScopedState;
     [border setClip];
+    NSGraphicsContext* context = [NSGraphicsContext currentContext];
     CGContextRef cgContext = (CGContextRef)[context graphicsPort];
     CGContextBeginTransparencyLayer(cgContext, NULL);
     CGContextSetAlpha(cgContext, 1 - morph);
     [context setPatternPhase:[[self window] themePatternPhase]];
     [self drawBackgroundWithOpaque:YES];
     CGContextEndTransparencyLayer(cgContext);
   }
 
   // Draw the border of the rounded rectangle.
   NSColor* borderColor = themeProvider->GetNSColor(
@@ skipping 13 matching lines @@
       NSMakePoint(morph * bookmarks::kNTPBookmarkBarPadding + morph * 0.5,
                   morph * bookmarks::kNTPBookmarkBarPadding + morph * 0.5);
   CGFloat dividerWidth =
       NSWidth(bounds) - 2 * morph * bookmarks::kNTPBookmarkBarPadding - 2 * 0.5;
   [divider moveToPoint:dividerStart];
   [divider relativeLineToPoint:NSMakePoint(dividerWidth, 0)];
   [divider stroke];
 }
 
 @end  // @implementation BookmarkBarToolbarView