Removed investigation CHECK from didCommitNavigation.

ios/web/web_state/ui/crw_wk_navigation_states_unittest.mm

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/web/web_state/ui/crw_wk_navigation_states.h"
 
 #import <WebKit/WebKit.h>
 
 #import "base/mac/scoped_nsobject.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 23 matching lines @@
 
   // navigation_2 is added later and hence the latest.
   [states_ setState:WKNavigationState::REQUESTED forNavigation:navigation2_];
   EXPECT_EQ(navigation2_, [states_ lastAddedNavigation]);
 
   // Updating state for existing navigation does not make it the latest.
   [states_ setState:WKNavigationState::STARTED forNavigation:navigation1_];
   EXPECT_EQ(navigation2_, [states_ lastAddedNavigation]);
 }
 
-// Tests |stateForNavigation:| method.
-TEST_F(CRWWKNavigationStatesTest, StateForNavigation) {
-  [states_ setState:WKNavigationState::REQUESTED forNavigation:navigation1_];
-  EXPECT_EQ(WKNavigationState::REQUESTED,
-            [states_ stateForNavigation:navigation1_]);
-
-  [states_ setState:WKNavigationState::REQUESTED forNavigation:navigation2_];
-  EXPECT_EQ(WKNavigationState::REQUESTED,
-            [states_ stateForNavigation:navigation2_]);
-
-  [states_ setState:WKNavigationState::STARTED forNavigation:navigation1_];
-  EXPECT_EQ(WKNavigationState::STARTED,
-            [states_ stateForNavigation:navigation1_]);
-}
-
 }  // namespace web