[ios-sdk] Removed string parameter from [FBSessionTokenCachingStrateg…

…y clearToken]

Summary:
The string parameter to this method was intended as an optimization to help implementations find
the token to be deleted. However, since the intention is that only the current token would ever be
deleted, they can store this data internally if they need to optimize for it, without requiring
that all callers pay the tax of passing it in.

Test Plan:
- Ran unit tests
- Ran SwitchUserSample (the only sample that used this method explicitly)

Revert Plan:

Reviewers: jacl, mmarucheck, gregschechte, ayden

Reviewed By: jacl

CC: msdkexp@

Differential Revision: https://phabricator.fb.com/D520450

Task ID: 1188716

samples/SwitchUserSample/SwitchUserSample/SUUserManager.m

@@ -141,7 +141,7 @@ - (void)updateUser:(NSDictionary<FBGraphUser> *)user inSlot:(int)slot {
         // FBSample logic
         // Also need to tell the token cache to forget the tokens for this user
         FBSessionTokenCachingStrategy *tokenCachingStrategy = [self createCachingStrategyForSlot:slot];
-        [tokenCachingStrategy clearToken:nil];
+        [tokenCachingStrategy clearToken];
 
         [defaults removeObjectForKey:idKey];
         [defaults removeObjectForKey:nameKey];

src/FBSession.m

@@ -262,7 +262,7 @@ - (id)initWithAppID:(NSString*)appID
                             shouldCache:NO];
             } else {
                 // else this token is expired and should be cleared from cache
-                [tokenCachingStrategy clearToken:cachedToken];
+                [tokenCachingStrategy clearToken];
             }
         }
     }
@@ -381,7 +381,7 @@ - (void)close {
 - (void)closeAndClearTokenInformation {
     NSAssert(self.affinitizedThread == [NSThread currentThread], @"FBSession: should only be used from a single thread");
 
-    [self.tokenCachingStrategy clearToken:self.accessToken];
+    [self.tokenCachingStrategy clearToken];
     [self transitionAndCallHandlerWithState:FBSessionStateClosed
                                       error:nil
                                       token:nil

src/FBSessionManualTokenCachingStrategy.m

@@ -41,7 +41,7 @@ - (NSDictionary*)fetchTokenInformation;
             nil];
 }
 
-- (void)clearToken:(NSString*)token
+- (void)clearToken
 {
     self.accessToken = nil;
     self.expirationDate = nil;

src/FBSessionTokenCachingStrategy.h

@@ -78,16 +78,9 @@
 
 /*!
  @abstract 
- Called by <FBSession> (and overridden by inheritors), in order delete any cached information for a given token
- 
- @discussion
- Not all implementations will make use of the token value passedas an argument; however advanced implementations
- may need the token value in order to locate and delete the cache. An overriding implementation must be able to
- tolerate a nil token, as well as a token value for which no cached information exists
- 
- @param token           the access token to clear
+ Called by <FBSession> (and overridden by inheritors), in order delete any cached information for the current token
  */
-- (void)clearToken:(NSString*)token;
+- (void)clearToken;
 
 /*!
  @abstract 

src/FBSessionTokenCachingStrategy.m

@@ -70,7 +70,7 @@ - (NSDictionary*)fetchTokenInformation {
     return [defaults objectForKey:_accessTokenInformationKeyName];
 }
 
-- (void)clearToken:(NSString*)token {        
+- (void)clearToken {        
     NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
     [defaults removeObjectForKey:_accessTokenInformationKeyName];
     [defaults synchronize];

src/Facebook.m

@@ -154,7 +154,7 @@ - (void)dealloc {
 - (void)invalidateSession {
 
     [self.session close];
-    [self.tokenCaching clearToken:nil];
+    [self.tokenCaching clearToken];
 
     [FBSession deleteFacebookCookies];
 
@@ -291,7 +291,7 @@ - (void)authorize:(NSArray *)permissions {
     // if we already have a session, git rid of it
     [self.session close];
     self.session = nil;
-    [self.tokenCaching clearToken:nil];
+    [self.tokenCaching clearToken];
 
     self.session = [[[FBSession alloc] initWithAppID:_appId
                                         permissions:permissions