Complete WebStateObserverBridge and follow Cocoa naming style.

ios/chrome/browser/autofill/form_input_accessory_view_controller.mm

Index: ios/chrome/browser/autofill/form_input_accessory_view_controller.mm
diff --git a/ios/chrome/browser/autofill/form_input_accessory_view_controller.mm b/ios/chrome/browser/autofill/form_input_accessory_view_controller.mm
index 8f82627b5b5bbff5330b9b73aced068e1911c2a6..97cf16481ae79b8e1c48c9b8ed92070a34bd4e41 100644
--- a/ios/chrome/browser/autofill/form_input_accessory_view_controller.mm
+++ b/ios/chrome/browser/autofill/form_input_accessory_view_controller.mm
@@ -362,20 +362,20 @@ bool ComputeFramesOfKeyboardParts(UIView* inputAccessoryView,
 #pragma mark -
 #pragma mark CRWWebStateObserver
 
-- (void)pageLoaded:(web::WebState*)webState {
+- (void)webStateDidLoadPage:(web::WebState*)webState {
   [self reset];
 }
 
-- (void)formActivity:(web::WebState*)webState
-            formName:(const std::string&)formName
-           fieldName:(const std::string&)fieldName
-                type:(const std::string&)type
-               value:(const std::string&)value
-             keyCode:(int)keyCode
-               error:(BOOL)error {
+- (void)webState:(web::WebState*)webState
+    didRegisterFormActivityWithFormNamed:(const std::string&)formName
+                               fieldName:(const std::string&)fieldName
+                                    type:(const std::string&)type
+                                   value:(const std::string&)value
+                                 keyCode:(int)keyCode
+                            inputMissing:(BOOL)inputMissing {
   web::URLVerificationTrustLevel trustLevel;
   const GURL pageURL(webState->GetCurrentURL(&trustLevel));
-  if (error || trustLevel != web::URLVerificationTrustLevel::kAbsolute ||
+  if (inputMissing || trustLevel != web::URLVerificationTrustLevel::kAbsolute ||
       !web::UrlHasWebScheme(pageURL) || !webState->ContentIsHTML()) {
     [self reset];
     return;