Cocoa: Update the current GL context when its window moves or resizes.

According to the NSOpenGLContext docs, you need to do this, and we were
 previously masking the need in the SDL_GL_MakeCurrent() implementation.

src/video/cocoa/SDL_cocoawindow.m

@@ -114,6 +114,7 @@ static __inline__ void ConvertNSRect(NSRect *r)
 - (void)windowDidMove:(NSNotification *)aNotification
 {
     int x, y;
+    SDL_VideoDevice *device = SDL_GetVideoDevice();
     SDL_Window *window = _data->window;
     NSWindow *nswindow = _data->nswindow;
     NSRect rect = [nswindow contentRectForFrameRect:[nswindow frame]];
@@ -136,17 +137,28 @@ static __inline__ void ConvertNSRect(NSRect *r)
 
     x = (int)rect.origin.x;
     y = (int)rect.origin.y;
+
+    if (window == device->current_glwin) {
+        [((NSOpenGLContext *) device->current_glctx) update];
+    }
+
     SDL_SendWindowEvent(window, SDL_WINDOWEVENT_MOVED, x, y);
 }
 
 - (void)windowDidResize:(NSNotification *)aNotification
 {
+    SDL_VideoDevice *device = SDL_GetVideoDevice();
     int w, h;
     NSRect rect = [_data->nswindow contentRectForFrameRect:[_data->nswindow frame]];
     w = (int)rect.size.width;
     h = (int)rect.size.height;
     if (SDL_IsShapedWindow(_data->window))
         Cocoa_ResizeWindowShape(_data->window);
+
+    if (_data->window == device->current_glwin) {
+        [((NSOpenGLContext *) device->current_glctx) update];
+    }
+
     SDL_SendWindowEvent(_data->window, SDL_WINDOWEVENT_RESIZED, w, h);
 }
 
@@ -683,6 +695,10 @@ Cocoa_SetWindowPosition(_THIS, SDL_Window * window)
     [nswindow setFrameOrigin:rect.origin];
     s_moveHack = moveHack;
 
+    if (window == _this->current_glwin) {
+        [((NSOpenGLContext *) _this->current_glctx) update];
+    }
+
     [pool release];
 }
 
@@ -690,12 +706,18 @@ void
 Cocoa_SetWindowSize(_THIS, SDL_Window * window)
 {
     NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
-    NSWindow *nswindow = ((SDL_WindowData *) window->driverdata)->nswindow;
+    SDL_WindowData *windata = (SDL_WindowData *) window->driverdata;
+    NSWindow *nswindow = windata->nswindow;
     NSSize size;
 
     size.width = window->w;
     size.height = window->h;
     [nswindow setContentSize:size];
+
+    if (window == _this->current_glwin) {
+        [((NSOpenGLContext *) _this->current_glctx) update];
+    }
+
     [pool release];
 }
 
@@ -738,6 +760,11 @@ Cocoa_MaximizeWindow(_THIS, SDL_Window * window)
     NSWindow *nswindow = ((SDL_WindowData *) window->driverdata)->nswindow;
 
     [nswindow zoom:nil];
+
+    if (window == _this->current_glwin) {
+        [((NSOpenGLContext *) _this->current_glctx) update];
+    }
+
     [pool release];
 }
 
@@ -856,6 +883,10 @@ Cocoa_SetWindowFullscreen(_THIS, SDL_Window * window, SDL_VideoDisplay * display
 #endif
     [nswindow makeKeyAndOrderFront:nil];
 
+    if (window == _this->current_glwin) {
+        [((NSOpenGLContext *) _this->current_glctx) update];
+    }
+
     [pool release];
 }