MacViews: Exploring removal of window-modal sheets.

chrome/browser/ui/cocoa/constrained_window/constrained_window_sheet_controller.mm

Index: chrome/browser/ui/cocoa/constrained_window/constrained_window_sheet_controller.mm
diff --git a/chrome/browser/ui/cocoa/constrained_window/constrained_window_sheet_controller.mm b/chrome/browser/ui/cocoa/constrained_window/constrained_window_sheet_controller.mm
index 92cdfa841099613b49dba258e52ccf2f979a2adb..a837c272ca85142c72570b6e299ae3e5bfc12487 100644
--- a/chrome/browser/ui/cocoa/constrained_window/constrained_window_sheet_controller.mm
+++ b/chrome/browser/ui/cocoa/constrained_window/constrained_window_sheet_controller.mm
@@ -134,6 +134,13 @@ NSRect GetSheetParentBoundsForParentView(NSView* view) {
            selector:@selector(onParentWindowWillClose:)
                name:NSWindowWillCloseNotification
              object:parentWindow_];
+
+    // Observe the parent window's size.
+    [[NSNotificationCenter defaultCenter]
+        addObserver:self
+           selector:@selector(onParentWindowSizeDidChange:)
+               name:NSWindowDidResizeNotification
+             object:parentWindow_];
   }
   return self;
 }
@@ -169,13 +176,6 @@ NSRect GetSheetParentBoundsForParentView(NSView* view) {
     return;
   }
 
-  // Observe the parent window's size.
-  [[NSNotificationCenter defaultCenter]
-      addObserver:self
-         selector:@selector(onParentWindowSizeDidChange:)
-             name:NSWindowDidResizeNotification
-           object:parentWindow_];
-
   // Create an invisible overlay window.
   NSRect rect = [self overlayWindowFrameForParentView:parentView];
   base::scoped_nsobject<NSWindow> overlayWindow(
@@ -267,10 +267,7 @@ NSRect GetSheetParentBoundsForParentView(NSView* view) {
 }
 
 - (void)onParentWindowWillClose:(NSNotification*)note {
-  [[NSNotificationCenter defaultCenter]
-      removeObserver:self
-                name:NSWindowWillCloseNotification
-              object:parentWindow_];
+  [[NSNotificationCenter defaultCenter] removeObserver:self];
 
   // Close all sheets.
   NSArray* sheets = [NSArray arrayWithArray:sheets_];
@@ -292,6 +289,8 @@ NSRect GetSheetParentBoundsForParentView(NSView* view) {
     return;
 
   [self updateSheetPosition:activeView_];
+  if (dialogHost_)
+    dialogHost_->OnPositionRequiresUpdate();
 }
 
 - (void)updateSheetPosition:(NSView*)parentView {
@@ -350,11 +349,6 @@ NSRect GetSheetParentBoundsForParentView(NSView* view) {
   if (![sheets_ containsObject:info])
     return;
 
-  [[NSNotificationCenter defaultCenter]
-      removeObserver:self
-                name:NSWindowDidResizeNotification
-              object:parentWindow_];
-
   if ([activeView_ isEqual:[info parentView]])
     activeView_.reset();