Bug 877767 - Draw window title on top of everything in drawintitlebar mode. r=smichaud

widget/cocoa/nsChildView.h

@@ -105,6 +105,18 @@ class GLManager;
 
 @interface NSView (Undocumented)
 
+// Draws the title string of a window.
+// Present on NSThemeFrame since at least 10.6.
+// _drawTitleBar is somewhat complex, and has changed over the years
+// since OS X 10.6.  But in that time it's never done anything that
+// would break when called outside of -[NSView drawRect:] (which we
+// sometimes do), or whose output can't be redirected to a
+// CGContextRef object (which we also sometimes do).  This is likely
+// to remain true for the indefinite future.  However we should
+// check _drawTitleBar in each new major version of OS X.  For more
+// information see bug 877767.
+- (void)_drawTitleBar:(NSRect)aRect;
+
 // Returns an NSRect that is the bounding box for all an NSView's dirty
 // rectangles (ones that need to be redrawn).  The full list of dirty
 // rectangles can be obtained by calling -[NSView _dirtyRegion] and then

widget/cocoa/nsChildView.mm

@@ -151,6 +151,7 @@ uint32_t nsChildView::sLastInputEventCount = 0;
 - (void)clearCorners;
 
 // Overlay drawing functions for traditional CGContext drawing
+- (void)drawTitleString;
 - (void)drawTitlebarHighlight;
 - (void)maskTopCornersInContext:(CGContextRef)aContext;
 
@@ -2096,6 +2097,11 @@ nsChildView::UpdateTitlebarImageBuffer()
   NSGraphicsContext* context = [NSGraphicsContext graphicsContextWithGraphicsPort:ctx flipped:[frameView isFlipped]];
   [NSGraphicsContext setCurrentContext:context];
 
+  // Draw the title string.
+  if ([frameView respondsToSelector:@selector(_drawTitleBar:)]) {
+    [frameView _drawTitleBar:[frameView bounds]];
+  }
+
   // Draw the titlebar controls into the titlebar image.
   for (id view in [window titlebarControls]) {
     NSRect viewFrame = [view frame];
@@ -3101,6 +3107,7 @@ NSEvent* gLastDragMouseDownEvent = nil;
   }
 
   if ([self isCoveringTitlebar]) {
+    [self drawTitleString];
     [self drawTitlebarHighlight];
     [self maskTopCornersInContext:aContext];
   }
@@ -3270,6 +3277,26 @@ NSEvent* gLastDragMouseDownEvent = nil;
   CGContextRestoreGState(aContext);
 }
 
+- (void)drawTitleString
+{
+  NSView* frameView = [[[self window] contentView] superview];
+  if (![frameView respondsToSelector:@selector(_drawTitleBar:)]) {
+    return;
+  }
+
+  NSGraphicsContext* oldContext = [NSGraphicsContext currentContext];
+  CGContextRef ctx = (CGContextRef)[oldContext graphicsPort];
+  CGContextSaveGState(ctx);
+  if ([oldContext isFlipped] != [frameView isFlipped]) {
+    CGContextTranslateCTM(ctx, 0, [self bounds].size.height);
+    CGContextScaleCTM(ctx, 1, -1);
+  }
+  [NSGraphicsContext setCurrentContext:[NSGraphicsContext graphicsContextWithGraphicsPort:ctx flipped:[frameView isFlipped]]];
+  [frameView _drawTitleBar:[frameView bounds]];
+  CGContextRestoreGState(ctx);
+  [NSGraphicsContext setCurrentContext:oldContext];
+}
+
 - (void)drawTitlebarHighlight
 {
   DrawTitlebarHighlight([self bounds].size, [self cornerRadius],