Revert of BackgroundGradientView: -drawBackground: → -drawRect:

chrome/browser/ui/cocoa/background_gradient_view.mm

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/ui/cocoa/background_gradient_view.h"
 
 #import "chrome/browser/themes/theme_properties.h"
 #import "chrome/browser/themes/theme_service.h"
 #import "chrome/browser/ui/cocoa/themed_window.h"
 #include "chrome/grit/theme_resources.h"
@@ skipping 33 matching lines @@
     return;
   showsDivider_ = show;
   [self setNeedsDisplay:YES];
 }
 
 - (NSPoint)patternPhase {
   return [[self window]
       themeImagePositionForAlignment:THEME_IMAGE_ALIGN_WITH_TAB_STRIP];
 }
 
-- (void)drawRect:(NSRect)dirtyRect {
+- (void)drawBackground:(NSRect)dirtyRect {
   [[NSGraphicsContext currentContext]
       cr_setPatternPhase:[self patternPhase]
                  forView:[self cr_viewBeingDrawnTo]];
 
   const ui::ThemeProvider* themeProvider = [[self window] themeProvider];
   if (themeProvider && !themeProvider->UsingSystemTheme()) {
     // If the background image is semi transparent then we need something
     // to blend against. Using 20% black gives us a color similar to Windows.
     [[NSColor colorWithCalibratedWhite:0.2 alpha:1.0] set];
     NSRectFill(dirtyRect);
@@ skipping 110 matching lines @@
 
 - (void)windowDidChangeTheme {
   [self setNeedsDisplay:YES];
 }
 
 - (void)windowDidChangeActive {
   [self setNeedsDisplay:YES];
 }
 
 @end