winemac: Ignore Cocoa child windows which aren't instances of WineWindow.

On Yosemite, in full-screen mode, Cocoa adds child windows of its own to our
windows.  These windows are, of course, not instances of WineWindow.  So, when
we call WineWindow-specific methods on them, it throws exceptions.

dlls/winemac.drv/cocoa_window.m

@@ -195,6 +195,8 @@ @interface WineWindow ()
 
 @property (retain, nonatomic) NSTimer* liveResizeDisplayTimer;
 
+@property (readonly, copy, nonatomic) NSArray* childWineWindows;
+
     - (void) updateColorSpace;
 
     - (BOOL) becameEligibleParentOrChild;
@@ -834,7 +836,7 @@ - (void) setMacDrvState:(const struct macdrv_window_state*)state
                 // Became non-floating.  If parent of floating children, make that
                 // relationship latent.
                 WineWindow* child;
-                for (child in [[[self childWindows] copy] autorelease])
+                for (child in [self childWineWindows])
                 {
                     if (child.floating)
                         [child becameIneligibleChild];
@@ -1012,7 +1014,7 @@ - (void) becameIneligibleChild
 
     - (void) becameIneligibleParentOrChild
     {
-        NSArray* childWindows = [self childWindows];
+        NSArray* childWindows = [self childWineWindows];
 
         [self becameIneligibleChild];
 
@@ -1020,7 +1022,6 @@ - (void) becameIneligibleParentOrChild
         {
             WineWindow* child;
 
-            childWindows = [[childWindows copy] autorelease];
             for (child in childWindows)
             {
                 child.latentParentWindow = self;
@@ -1101,7 +1102,7 @@ - (void) order:(NSWindowOrderingMode)mode childWindow:(WineWindow*)child relativ
 
         // Get our child windows and sort them in the reverse of the desired
         // z-order (back-to-front).
-        origChildren = [self childWindows];
+        origChildren = [self childWineWindows];
         children = [[origChildren mutableCopy] autorelease];
         [children sortWithOptions:NSSortStable
                   usingComparator:^NSComparisonResult(id obj1, id obj2){
@@ -1315,7 +1316,7 @@ - (void) setFrameFromWine:(NSRect)contentRect
                     [self setContentMaxSize:NSMakeSize(FLT_MAX, FLT_MAX)];
                 }
 
-                if (equalSizes && [[self childWindows] count])
+                if (equalSizes && [[self childWineWindows] count])
                 {
                     // If we change the window frame such that the origin moves
                     // but the size doesn't change, then Cocoa moves child
@@ -1611,6 +1612,15 @@ - (void) toggleFullScreen:(id)sender
             [super toggleFullScreen:sender];
     }
 
+    - (NSArray*) childWineWindows
+    {
+        NSArray* childWindows = self.childWindows;
+        NSIndexSet* indexes = [childWindows indexesOfObjectsPassingTest:^BOOL(id child, NSUInteger idx, BOOL *stop){
+            return [child isKindOfClass:[WineWindow class]];
+        }];
+        return [childWindows objectsAtIndexes:indexes];
+    }
+
     // We normally use the generic/calibrated RGB color space for the window,
     // rather than the device color space, to avoid expensive color conversion
     // which slows down drawing.  However, for windows displaying OpenGL, having