OSX/Cocoa : discard Cocoa GL view flush while in live resize, and send Window size change ghost message only when user releases mouse button (not in live resize).

Potentially fixing bug [#23561]

intern/ghost/intern/GHOST_SystemCocoa.mm

@@ -987,6 +987,8 @@ bool GHOST_SystemCocoa::processEvents(bool waitForEvent)
 		return true;
 	}
 	
+	m_ignoreWindowSizedMessages = false;
+	
     return anyProcessed;
 }
 
@@ -1054,8 +1056,10 @@ GHOST_TSuccess GHOST_SystemCocoa::handleWindowEvent(GHOST_TEventType eventType,
 			case GHOST_kEventWindowSize:
 				if (!m_ignoreWindowSizedMessages)
 				{
+					//Enforce only one resize message per event loop (coalescing all the live resize messages)					
 					window->updateDrawingContext();
 					pushEvent( new GHOST_Event(getMilliSeconds(), GHOST_kEventWindowSize, window) );
+					m_ignoreWindowSizedMessages = true;
 				}
 				break;
 			default:

intern/ghost/intern/GHOST_WindowCocoa.mm

@@ -280,6 +280,18 @@ extern "C" {
     return YES;
 }
 
+- (void) drawRect:(NSRect)rect
+{
+    if ([self inLiveResize])
+    {
+        //Don't redraw while in live resize
+    }
+    else
+    {
+        [super drawRect:rect];
+    }
+}
+
 @end