move `RCTBatchedBridge` interface to a private header

Summary:Interface to `RCTBatchedBridge` was being declared in two different implementation files. This is suboptimal, since it makes it hard to mock that class in a test.
So I've merged and moved these two definitions in `RCTBridge+Private.h`, so it's still obvious it's a private class, but can be included if you really need it.

Reviewed By: javache

Differential Revision: D3126135

fb-gh-sync-id: 173e4c5c2925be387b92deb7f99952ca7bf28588
fbshipit-source-id: 173e4c5c2925be387b92deb7f99952ca7bf28588

React/Base/RCTBatchedBridge.m

@@ -41,14 +41,6 @@ typedef NS_ENUM(NSUInteger, RCTBridgeFields) {
 
 RCT_EXTERN NSArray<Class> *RCTGetModuleClasses(void);
 
-@interface RCTBatchedBridge : RCTBridge
-
-@property (nonatomic, weak) RCTBridge *parentBridge;
-@property (nonatomic, weak) id<RCTJavaScriptExecutor> javaScriptExecutor;
-@property (nonatomic, assign) BOOL moduleSetupComplete;
-
-@end
-
 @implementation RCTBatchedBridge
 {
   BOOL _wasBatchActive;

React/Base/RCTBridge+Private.h

@@ -117,3 +117,13 @@
 - (void)_immediatelyCallTimer:(NSNumber *)timer;
 
 @end
+
+@interface RCTBatchedBridge : RCTBridge <RCTInvalidating>
+
+@property (nonatomic, weak) RCTBridge *parentBridge;
+@property (nonatomic, weak) id<RCTJavaScriptExecutor> javaScriptExecutor;
+@property (nonatomic, assign) BOOL moduleSetupComplete;
+
+- (instancetype)initWithParentBridge:(RCTBridge *)bridge NS_DESIGNATED_INITIALIZER;
+
+@end

React/Base/RCTBridge.m

@@ -25,14 +25,6 @@ NSString *const RCTJavaScriptDidLoadNotification = @"RCTJavaScriptDidLoadNotific
 NSString *const RCTJavaScriptDidFailToLoadNotification = @"RCTJavaScriptDidFailToLoadNotification";
 NSString *const RCTDidInitializeModuleNotification = @"RCTDidInitializeModuleNotification";
 
-@interface RCTBatchedBridge : RCTBridge <RCTInvalidating>
-
-@property (nonatomic, weak) RCTBridge *parentBridge;
-
-- (instancetype)initWithParentBridge:(RCTBridge *)bridge NS_DESIGNATED_INITIALIZER;
-
-@end
-
 static NSMutableArray<Class> *RCTModuleClasses;
 NSArray<Class> *RCTGetModuleClasses(void);
 NSArray<Class> *RCTGetModuleClasses(void)