#1562 Rename 'tick' to 'onTick' to pass iTunes Connect validation.

Summary:
Should close this issue and successfully pass iTunes Connect validation.
Closes https://github.com/facebook/react-native/pull/1722
Github Author: Matt Revell <mattrevell82@me.com>

Test Plan: Imported from GitHub, without a `Test Plan:` line.

React/Base/RCTBatchedBridge.m

@@ -721,7 +721,7 @@ RCT_NOT_IMPLEMENTED(-initWithBundleURL:(__unused NSURL *)bundleURL
   RCTProfileEndEvent(@"DispatchFrameUpdate", @"objc_call", nil);
 
   dispatch_async(dispatch_get_main_queue(), ^{
-    [self.perfStats.jsGraph tick:displayLink.timestamp];
+    [self.perfStats.jsGraph onTick:displayLink.timestamp];
   });
 }
 
@@ -731,7 +731,7 @@ RCT_NOT_IMPLEMENTED(-initWithBundleURL:(__unused NSURL *)bundleURL
 
   RCTProfileImmediateEvent(@"VSYNC", displayLink.timestamp, @"g");
 
-  [self.perfStats.uiGraph tick:displayLink.timestamp];
+  [self.perfStats.uiGraph onTick:displayLink.timestamp];
 }
 
 - (void)startProfiling

React/Base/RCTFPSGraph.h

@@ -18,6 +18,6 @@ typedef NS_ENUM(NSUInteger, RCTFPSGraphPosition) {
 
 - (instancetype)initWithFrame:(CGRect)frame graphPosition:(RCTFPSGraphPosition)position name:(NSString *)name color:(UIColor *)color NS_DESIGNATED_INITIALIZER;
 
-- (void)tick:(NSTimeInterval)timestamp;
+- (void)onTick:(NSTimeInterval)timestamp;
 
 @end

React/Base/RCTFPSGraph.m

@@ -93,7 +93,7 @@ RCT_NOT_IMPLEMENTED(-initWithCoder:(NSCoder *)aDecoder)
   return label;
 }
 
-- (void)tick:(NSTimeInterval)timestamp
+- (void)onTick:(NSTimeInterval)timestamp
 {
   _frameCount++;
   if (_prevTime == -1) {