Add and use gfx::ScopedNSGraphicsContextState (ui/gfx/scoped_ns_graphics_context_state_mac.h).

chrome/browser/ui/cocoa/tabs/tab_view.mm

Index: chrome/browser/ui/cocoa/tabs/tab_view.mm
diff --git a/chrome/browser/ui/cocoa/tabs/tab_view.mm b/chrome/browser/ui/cocoa/tabs/tab_view.mm
index 25b62fe20b762b1c91c3e09e296f4def8bfad53f..1a5e1df7d2bc3aa020f74e2c7d8a9b403491926b 100644
--- a/chrome/browser/ui/cocoa/tabs/tab_view.mm
+++ b/chrome/browser/ui/cocoa/tabs/tab_view.mm
@@ -17,6 +17,7 @@
 #include "grit/theme_resources.h"
 #include "grit/theme_resources_standard.h"
 #include "ui/base/l10n/l10n_util.h"
+#include "ui/gfx/scoped_ns_graphics_context_state_mac.h"
 
 namespace {
 
@@ -652,7 +653,7 @@ const CGFloat kRapidCloseDist = 2.5;
   const CGFloat lineWidth = [self cr_lineWidth];
 
   NSGraphicsContext* context = [NSGraphicsContext currentContext];
-  [context saveGraphicsState];
+  gfx::ScopedNSGraphicsContextState scopedGState(context);
 
   ThemeService* themeProvider =
       static_cast<ThemeService*>([[self window] themeProvider]);
@@ -701,7 +702,7 @@ const CGFloat kRapidCloseDist = 2.5;
   CGFloat alertAlpha = [self alertAlpha];
   if (selected || hoverAlpha > 0 || alertAlpha > 0) {
     // Draw the selected background / glow overlay.
-    [context saveGraphicsState];
+    gfx::ScopedNSGraphicsContextState drawHoverState(context);
     CGContextRef cgContext = static_cast<CGContextRef>([context graphicsPort]);
     CGContextBeginTransparencyLayer(cgContext, 0);
     if (!selected) {
@@ -712,9 +713,10 @@ const CGFloat kRapidCloseDist = 2.5;
       CGContextSetAlpha(cgContext, backgroundAlpha);
     }
     [path addClip];
-    [context saveGraphicsState];
-    [super drawBackground];
-    [context restoreGraphicsState];
+    {
+      gfx::ScopedNSGraphicsContextState drawBackgroundState(context);
+      [super drawBackground];
+    }
 
     // Draw a mouse hover gradient for the default themes.
     if (!selected && hoverAlpha > 0) {
@@ -738,7 +740,6 @@ const CGFloat kRapidCloseDist = 2.5;
     }
 
     CGContextEndTransparencyLayer(cgContext);
-    [context restoreGraphicsState];
   }
 
   BOOL active = [[self window] isKeyWindow] || [[self window] isMainWindow];
@@ -768,11 +769,12 @@ const CGFloat kRapidCloseDist = 2.5;
   [context restoreGraphicsState];
 
   // Draw the top stroke.
-  [context saveGraphicsState];
-  [borderColor set];
-  [path setLineWidth:lineWidth];
-  [path stroke];
-  [context restoreGraphicsState];
+  {
+    gfx::ScopedNSGraphicsContextState drawBorderState(context);
+    [borderColor set];
+    [path setLineWidth:lineWidth];
+    [path stroke];
+  }
 
   // Mimic the tab strip's bottom border, which consists of a dark border
   // and light highlight.
@@ -788,8 +790,6 @@ const CGFloat kRapidCloseDist = 2.5;
     [highlightColor set];
     NSRectFillUsingOperation(borderRect, NSCompositeSourceOver);
   }
-
-  [context restoreGraphicsState];
 }
 
 - (void)viewDidMoveToWindow {