[Mac][MC] Allow right click to open the message center tray.

ui/message_center/cocoa/status_item_view.mm

Index: ui/message_center/cocoa/status_item_view.mm
diff --git a/ui/message_center/cocoa/status_item_view.mm b/ui/message_center/cocoa/status_item_view.mm
index 305929332416862e0c1b15271b206a200c659b18..b884ae6dea2c467a91d1a58ee81a1e1a504b6408 100644
--- a/ui/message_center/cocoa/status_item_view.mm
+++ b/ui/message_center/cocoa/status_item_view.mm
@@ -55,7 +55,6 @@ const CGFloat kInset = 6;
 }
 
 - (void)mouseDown:(NSEvent*)event {
-  DCHECK(!inMouseEventSequence_);
   inMouseEventSequence_ = YES;
   [self setNeedsDisplay:YES];
 
@@ -64,11 +63,26 @@ const CGFloat kInset = 6;
 }
 
 - (void)mouseUp:(NSEvent*)event {
-  DCHECK(inMouseEventSequence_);
   inMouseEventSequence_ = NO;
   [self setNeedsDisplay:YES];
 }
 
+- (void)rightMouseDown:(NSEvent*)event {
+  [self mouseDown:event];
+}
+
+- (void)rightMouseUp:(NSEvent*)event {
+  [self mouseUp:event];
+}
+
+- (void)otherMouseDown:(NSEvent*)event {
+  [self mouseDown:event];
+}
+
+- (void)otherMouseUp:(NSEvent*)event {
+  [self mouseUp:event];
+}
+
 - (void)drawRect:(NSRect)dirtyRect {
   NSRect frame = [self bounds];