Fix SDK forward declarations after CL 530193004

The APIs that need forward declarations were actually introduced in
OS X 10.7 SDK instead of 10.9 SDK, forward declare them in the wrong
place will cause build issue when using older SDKs like 10.7 or 10.8.

BUG=390212

Review URL: https://codereview.chromium.org/555163002

Cr-Commit-Position: refs/heads/master@{#294013}

base/mac/sdk_forward_declarations.h

@@ -152,8 +152,27 @@ enum CWChannelBand {
 @property(readonly) CWChannelBand channelBand;
 @end
 
+enum {
+   kCWSecurityNone = 0,
+   kCWSecurityWEP = 1,
+   kCWSecurityWPAPersonal = 2,
+   kCWSecurityWPAPersonalMixed = 3,
+   kCWSecurityWPA2Personal = 4,
+   kCWSecurityPersonal = 5,
+   kCWSecurityDynamicWEP = 6,
+   kCWSecurityWPAEnterprise = 7,
+   kCWSecurityWPAEnterpriseMixed = 8,
+   kCWSecurityWPA2Enterprise = 9,
+   kCWSecurityEnterprise = 10,
+   kCWSecurityUnknown = NSIntegerMax,
+};
+
+typedef NSInteger CWSecurity;
+
 @interface CWNetwork (LionSDK)
 @property(readonly) CWChannel* wlanChannel;
+@property(readonly) NSInteger rssiValue;
+- (BOOL)supportsSecurity:(CWSecurity)security;
 @end
 
 @interface IOBluetoothHostController (LionSDK)
@@ -257,31 +276,6 @@ typedef NSUInteger NSWindowOcclusionState;
 - (NSWindowOcclusionState)occlusionState;
 @end
 
-// 10.6 SDK don't have CWSecurity while 10.9 SDK don't have CWSecurityMode, to
-// build with SDKs from 10.6 to 10.9 both need to be forward declared and use
-// runtime checks to ensure correct methods are used on different OS X versions.
-enum {
-   kCWSecurityNone = 0,
-   kCWSecurityWEP = 1,
-   kCWSecurityWPAPersonal = 2,
-   kCWSecurityWPAPersonalMixed = 3,
-   kCWSecurityWPA2Personal = 4,
-   kCWSecurityPersonal = 5,
-   kCWSecurityDynamicWEP = 6,
-   kCWSecurityWPAEnterprise = 7,
-   kCWSecurityWPAEnterpriseMixed = 8,
-   kCWSecurityWPA2Enterprise = 9,
-   kCWSecurityEnterprise = 10,
-   kCWSecurityUnknown = NSIntegerMax,
-};
-
-typedef NSInteger CWSecurity;
-
-@interface CWNetwork (MavericksSDK)
-@property(readonly) NSInteger rssiValue;
-- (BOOL)supportsSecurity:(CWSecurity)security;
-@end
-
 #else  // !MAC_OS_X_VERSION_10_9
 
 typedef enum {