Fix a hang on 10.11 caused by -[MDHoverButton layout] making itself need layout.

Updating self.image (on an NSButton subclass) in -layout or -viewWillDraw both
seem to lead to an infinite loop in 10.11. I'm not sure if there's a better way
to fix this; using different triggers to update the image seems safest.

Bug: 805109
Change-Id: I468576069f44eae4a2f4b9058e078d88d157265a
Reviewed-on: https://chromium-review.googlesource.com/899586Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Sidney San Martín <sdy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534137}

chrome/browser/ui/cocoa/md_hover_button.h

@@ -7,13 +7,14 @@
 
 #import <AppKit/AppKit.h>
 
+#import "chrome/browser/ui/cocoa/themed_window.h"
 #import "ui/base/cocoa/hover_button.h"
 #include "ui/gfx/vector_icon_types.h"
 
 // MDHoverButton has a gray background with rounded corners. The background is
 // only visible on hover and gets darker on click. It's friendly to subviews.
 
-@interface MDHoverButton : HoverButton
+@interface MDHoverButton : HoverButton<ThemedWindowDrawing>
 
 // An icon that's displayed in the middle of the button.
 @property(nonatomic) const gfx::VectorIcon* icon;

chrome/browser/ui/cocoa/md_hover_button.mm

@@ -6,7 +6,6 @@
 
 #import <QuartzCore/QuartzCore.h>
 
-#import "chrome/browser/ui/cocoa/themed_window.h"
 #import "ui/base/cocoa/nsview_additions.h"
 #include "ui/base/theme_provider.h"
 #include "ui/gfx/color_palette.h"
@@ -49,12 +48,12 @@ NSColor* GetActiveColor(BOOL dark_theme) {
 
 - (void)setIcon:(const gfx::VectorIcon*)icon {
   icon_ = icon;
-  self.needsLayout = YES;
+  [self updateIcon];
 }
 
 - (void)setIconSize:(int)iconSize {
   iconSize_ = iconSize;
-  self.needsLayout = YES;
+  [self updateIcon];
 }
 
 - (void)setHoverSuppressed:(BOOL)hoverSuppressed {
@@ -71,6 +70,15 @@ NSColor* GetActiveColor(BOOL dark_theme) {
       provider->ShouldIncreaseContrast() ? 0xFF : kIconAlpha);
 }
 
+- (void)updateIcon {
+  if (!icon_ || icon_->is_empty() || iconSize_ == 0) {
+    self.image = nil;
+    return;
+  }
+  self.image = NSImageFromImageSkia(
+      gfx::CreateVectorIcon(*icon_, iconSize_, [self iconColor]));
+}
+
 - (void)updateHoverButtonAppearanceAnimated:(BOOL)animated {
   const BOOL darkTheme = [[self window] hasDarkTheme];
   const CGColorRef targetBackgroundColor = [&]() -> CGColorRef {
@@ -116,16 +124,6 @@ NSColor* GetActiveColor(BOOL dark_theme) {
 
 // NSView overrides.
 
-- (void)layout {
-  if (!icon_ || icon_->is_empty() || iconSize_ == 0) {
-    self.image = nil;
-    return;
-  }
-  self.image = NSImageFromImageSkia(
-      gfx::CreateVectorIcon(*icon_, iconSize_, [self iconColor]));
-  [super layout];
-}
-
 - (void)drawFocusRingMask {
   CGFloat radius = self.layer.cornerRadius;
   [[NSBezierPath bezierPathWithRoundedRect:self.bounds
@@ -133,4 +131,18 @@ NSColor* GetActiveColor(BOOL dark_theme) {
                                    yRadius:radius] fill];
 }
 
+- (void)viewDidMoveToWindow {
+  [super viewDidMoveToWindow];
+  [self updateIcon];
+}
+
+// ThemedWindowDrawing implementation
+
+- (void)windowDidChangeTheme {
+  [self updateIcon];
+}
+
+- (void)windowDidChangeActive {
+}
+
 @end