[Mac] Break stale controller refs in infobar close.

chrome/browser/ui/cocoa/infobars/infobar_controller.mm

Index: chrome/browser/ui/cocoa/infobars/infobar_controller.mm
diff --git a/chrome/browser/ui/cocoa/infobars/infobar_controller.mm b/chrome/browser/ui/cocoa/infobars/infobar_controller.mm
index eabf4a9b88999512d904033c96bcb3a1c1ea5928..6e9e79f1eb87b0cf5a1b82ea45aef32f2f0848eb 100644
--- a/chrome/browser/ui/cocoa/infobars/infobar_controller.mm
+++ b/chrome/browser/ui/cocoa/infobars/infobar_controller.mm
@@ -78,6 +78,7 @@ const float kAnimateCloseDuration = 0.12;
     labelFrame.size.width += NSMinX(imageFrame) - NSMinX(labelFrame);
     labelFrame.origin.x = imageFrame.origin.x;
     [image_ removeFromSuperview];
+    image_ = nil;
     [labelPlaceholder_ setFrame:labelFrame];
   }
   [self initializeLabel];
@@ -88,6 +89,13 @@ const float kAnimateCloseDuration = 0.12;
   [infoBarView_ setInfobarType:delegate_->GetInfoBarType()];
 }
 
+- (void)dealloc {
+  [okButton_ setTarget:nil];
+  [cancelButton_ setTarget:nil];
+  [closeButton_ setTarget:nil];
+  [super dealloc];
+}
+
 // Called when someone clicks on the embedded link.
 - (BOOL) textView:(NSTextView*)textView
     clickedOnLink:(id)link
@@ -176,7 +184,9 @@ const float kAnimateCloseDuration = 0.12;
   NSRect labelFrame = [label_.get() frame];
   labelFrame.size.width = NSMaxX([cancelButton_ frame]) - NSMinX(labelFrame);
   [okButton_ removeFromSuperview];
+  okButton_ = nil;
   [cancelButton_ removeFromSuperview];
+  cancelButton_ = nil;
   [label_.get() setFrame:labelFrame];
 }
 
@@ -359,6 +369,7 @@ const float kAnimateCloseDuration = 0.12;
     rightEdge = NSMinX(okButtonFrame);
   } else {
     [okButton_ removeFromSuperview];
+    okButton_ = nil;
   }
 
   // Update and position the Cancel button if needed.  Otherwise, hide it.
@@ -381,6 +392,7 @@ const float kAnimateCloseDuration = 0.12;
     rightEdge = NSMinX(cancelButtonFrame);
   } else {
     [cancelButton_ removeFromSuperview];
+    cancelButton_ = nil;
   }
 
   // If we had either button, leave space before the edge of the textfield.