mac: Move more 10.7 api stuff into sdk_forward_declarations.h

media/video/capture/screen/mac/desktop_configuration.mm

Index: media/video/capture/screen/mac/desktop_configuration.mm
diff --git a/media/video/capture/screen/mac/desktop_configuration.mm b/media/video/capture/screen/mac/desktop_configuration.mm
index 53b8e1377952e4de087b4e1bffed9828f0406b0b..633389c47727860d935e64ba5bef2f2e840d132b 100644
--- a/media/video/capture/screen/mac/desktop_configuration.mm
+++ b/media/video/capture/screen/mac/desktop_configuration.mm
@@ -9,16 +9,7 @@
 #include <Cocoa/Cocoa.h>
 
 #include "base/logging.h"
-
-#if !defined(MAC_OS_X_VERSION_10_7) || \
-    MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_7
-
-@interface NSScreen (LionAPI)
-- (CGFloat)backingScaleFactor;
-- (NSRect)convertRectToBacking:(NSRect)aRect;
-@end
-
-#endif  // 10.7
+#include "base/mac/sdk_forward_declarations.h"
 
 namespace media {
 
@@ -68,7 +59,7 @@ MacDisplayConfiguration GetConfigurationForScreen(NSScreen* screen) {
   if ([screen respondsToSelector:@selector(backingScaleFactor)] &&
       [screen respondsToSelector:@selector(convertRectToBacking:)]) {
     display_config.dip_to_pixel_scale = [screen backingScaleFactor];
-    NSRect ns_pixel_bounds = [screen convertRectToBacking: ns_bounds];
+    NSRect ns_pixel_bounds = [screen convertRectToBacking:ns_bounds];
     display_config.pixel_bounds = NSRectToDesktopRect(ns_pixel_bounds);
   } else {
     display_config.pixel_bounds = display_config.bounds;