mac: attempt to fix a startup perf regression after r174653

chrome/browser/ui/cocoa/image_button_cell.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/image_button_cell.h"
 
 #include "base/logging.h"
 #import "chrome/browser/themes/theme_service.h"
 #import "chrome/browser/ui/cocoa/themed_window.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 40 matching lines @@
 }
 
 - (void)sharedInit {
   [self setHighlightsBy:NSNoCellMask];
 
   // We need to set this so that we can override |-mouseEntered:| and
   // |-mouseExited:| to change the button image on hover states.
   [self setShowsBorderOnlyWhileMouseInside:YES];
 }
 
+- (NSImage*)imageForState:(image_button_cell::ButtonState)state
+                     view:(NSView*)controlView{
+  if (image_[state].imageId)
+    return [self imageForID:image_[state].imageId controlView:controlView];
+  return image_[state].image;
+}
+
 - (void)drawWithFrame:(NSRect)cellFrame inView:(NSView*)controlView {
+  image_button_cell::ButtonState state = [self currentButtonState];
   BOOL windowHasFocus = [[controlView window] isMainWindow] ||
                         [[controlView window] isKeyWindow];
   CGFloat alpha = windowHasFocus ? 1.0 : kImageNoFocusAlpha;
-  NSImage* image = image_[[self currentButtonState]];
+  NSImage* image = [self imageForState:state view:controlView];
 
   if (!windowHasFocus) {
+    NSImage* defaultImage = [self
+      imageForState:image_button_cell::kDefaultStateBackground
+               view:controlView];
+    NSImage* hoverImage = [self
+      imageForState:image_button_cell::kHoverStateBackground
+               view:controlView];
     if ([self currentButtonState] == image_button_cell::kDefaultState &&
-        image_[image_button_cell::kDefaultStateBackground]) {
-      image = image_[image_button_cell::kDefaultStateBackground];
+        defaultImage) {
+      image = defaultImage;
       alpha = 1.0;
     } else if ([self currentButtonState] == image_button_cell::kHoverState &&
-        image_[image_button_cell::kHoverStateBackground]) {
-      image = image_[image_button_cell::kHoverStateBackground];
+        hoverImage) {
+      image = hoverImage;
       alpha = 1.0;
     }
   }
 
   NSRect imageRect;
   imageRect.size = [image size];
   imageRect.origin.x = cellFrame.origin.x +
     roundf((NSWidth(cellFrame) - NSWidth(imageRect)) / 2.0);
   imageRect.origin.y = cellFrame.origin.y +
     roundf((NSHeight(cellFrame) - NSHeight(imageRect)) / 2.0);
@@ skipping 18 matching lines @@
                     fromRect:NSZeroRect
                    operation:NSCompositeSourceOver
                     fraction:1.0
               respectFlipped:YES
                        hints:nil];
   }
 }
 
 - (void)setImageID:(NSInteger)imageID
     forButtonState:(image_button_cell::ButtonState)state {
-  ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
-  NSImage* image = imageID ? rb.GetNativeImageNamed(imageID).ToNSImage() : nil;
-  [self setImage:image forButtonState:state];
+  DCHECK_GE(state, 0);
+  DCHECK_LT(state, image_button_cell::kButtonStateCount);
+
+  image_[state].image.reset();
+  image_[state].imageId = imageID;
+  [[self controlView] setNeedsDisplay:YES];
 }
 
 // Sets the image for the given button state using an image.
 - (void)setImage:(NSImage*)image
   forButtonState:(image_button_cell::ButtonState)state {
   DCHECK_GE(state, 0);
   DCHECK_LT(state, image_button_cell::kButtonStateCount);
-  image_[state].reset([image retain]);
+
+  image_[state].image.reset([image retain]);
+  image_[state].imageId = 0;
   [[self controlView] setNeedsDisplay:YES];
 }
 
 - (void)setOverlayImageID:(NSInteger)imageID {
   if (overlayImageID_ != imageID) {
     overlayImageID_ = imageID;
     [[self controlView] setNeedsDisplay:YES];
   }
 }
 
 - (image_button_cell::ButtonState)currentButtonState {
-  if (![self isEnabled] && image_[image_button_cell::kDisabledState])
+  bool (^has)(image_button_cell::ButtonState) =
+      ^(image_button_cell::ButtonState state) {
+          return image_[state].image || image_[state].imageId;
+      };
+  if (![self isEnabled] && has(image_button_cell::kDisabledState))
     return image_button_cell::kDisabledState;
-  else if ([self isHighlighted] && image_[image_button_cell::kPressedState])
+  if ([self isHighlighted] && has(image_button_cell::kPressedState))
     return image_button_cell::kPressedState;
-  else if ([self isMouseInside] && image_[image_button_cell::kHoverState])
+  if ([self isMouseInside] && has(image_button_cell::kHoverState))
     return image_button_cell::kHoverState;
-  else
-    return image_button_cell::kDefaultState;
+  return image_button_cell::kDefaultState;
 }
 
 - (NSImage*)imageForID:(NSInteger)imageID
            controlView:(NSView*)controlView {
   if (!imageID)
     return nil;
 
   ui::ThemeProvider* themeProvider = [[controlView window] themeProvider];
   if (!themeProvider)
     return nil;
@@ skipping 25 matching lines @@
 
 - (void)mouseEntered:(NSEvent*)theEvent {
   [self setIsMouseInside:YES];
 }
 
 - (void)mouseExited:(NSEvent*)theEvent {
   [self setIsMouseInside:NO];
 }
 
 @end