Fix typos (#2576)

Author: paulb777

Example/Auth/Tests/FIROAuthProviderTests.m

@@ -80,7 +80,7 @@
 static NSString *const kFakeReverseClientID = @"com.googleusercontent.apps.123456";
 
 /** @var kFakeOAuthResponseURL
-    @brief A fake OAuth reponse URL used in test.
+    @brief A fake OAuth response URL used in test.
  */
 static NSString *const kFakeOAuthResponseURL = @"fakeOAuthResponseURL";
 

Firebase/Auth/Source/AuthProviders/OAuth/FIROAuthProvider.m

@@ -37,7 +37,7 @@
 /** @typedef FIRHeadfulLiteURLCallBack
     @brief The callback invoked at the end of the flow to fetch a headful-lite URL.
     @param headfulLiteURL The headful lite URL.
-    @param error The error that occured while fetching the headful-lite, if any.
+    @param error The error that occurred while fetching the headful-lite, if any.
  */
 typedef void (^FIRHeadfulLiteURLCallBack)(NSURL *_Nullable headfulLiteURL,
                NSError *_Nullable error);
@@ -167,7 +167,7 @@ - (void)getCredentialWithUIDelegate:(nullable id<FIRAuthUIDelegate>)UIDelegate
 #pragma mark - Internal Methods
 
 /** @fn initWithProviderID:auth:
-    @brief returns an instance of @c FIROAuthProvider assocaited with the provided auth instance.
+    @brief returns an instance of @c FIROAuthProvider associated with the provided auth instance.
     @param auth The Auth instance to be associated with the OAuthProvider instance.
     @return An Instance of @c FIROAuthProvider.
   */
@@ -314,7 +314,7 @@ - (nullable NSString *)customParametersStringWithError:(NSError *_Nullable *_Nul
 }
 
 /** @fn hashforString:
-    @brief Returns the SHA256 hash representaion of a given string object.
+    @brief Returns the SHA256 hash representation of a given string object.
     @param string The string for which a SHA256 hash is desired.
     @return An hexadecimal string representation of the SHA256 hash.
  */

Firebase/Auth/Source/FIRAuthInternalErrors.h

@@ -355,7 +355,7 @@ typedef NS_ENUM(NSInteger, FIRAuthInternalErrorCode) {
   FIRAuthInternalErrorCodeWebInternalError =
       FIRAuthPublicErrorCodeFlag | FIRAuthErrorCodeWebInternalError,
 
-  /** Indicates that an internal error occured within a SFSafariViewController or UIWebview.
+  /** Indicates that an internal error occurred within a SFSafariViewController or UIWebview.
    */
   FIRAuthInternalErrorCodeWebSignInUserInteractionFailure =
       FIRAuthPublicErrorCodeFlag | FIRAuthErrorCodeWebSignInUserInteractionFailure,

Firebase/Auth/Source/FIRUser.m

@@ -1191,7 +1191,7 @@ - (void)unlinkFromProvider:(NSString *)provider
           return;
         }
 
-        // We can't just use the provider info objects in FIRSetAcccountInfoResponse because they
+        // We can't just use the provider info objects in FIRSetAccountInfoResponse because they
         // don't have localID and email fields. Remove the specific provider manually.
         NSMutableDictionary *mutableProviderData = [self->_providerData mutableCopy];
         [mutableProviderData removeObjectForKey:provider];

Firebase/Auth/Source/Public/FIRAuth.h

@@ -487,7 +487,7 @@ NS_SWIFT_NAME(Auth)
         <li>@c FIRAuthErrorCodeWebNetworkRequestFailed - Indicates that a network request within a
             SFSafariViewController or UIWebview failed.
         </li>
-        <li>@c FIRAuthErrorCodeWebInternalError - Indicates that an internal error occured within a
+        <li>@c FIRAuthErrorCodeWebInternalError - Indicates that an internal error occurred within a
             SFSafariViewController or UIWebview.
         </li>
         <li>@c FIRAuthErrorCodeWebSignInUserInteractionFailure - Indicates a general failure during