Remove -[CRWNativeContent dismissKeyboard].

This optional method is not implemented by native content classes.

Bug: 725239
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I70bb3e0e308762bd90c354769eccd1cc2616ed73
Reviewed-on: https://chromium-review.googlesource.com/1073676Reviewed-by: Kurt Horimoto <kkhorimoto@chromium.org>
Commit-Queue: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562024}

ios/chrome/browser/ui/browser_view_controller.mm

@@ -1471,9 +1471,6 @@ applicationCommandEndpoint:(id<ApplicationCommands>)applicationCommandEndpoint {
   // dismiss the keyboard.
   [self closeFindInPage];
   [_model.currentTab.view endEditing:NO];
-  id nativeController = [self nativeControllerForTab:_model.currentTab];
-  if ([nativeController respondsToSelector:@selector(dismissKeyboard)])
-    [nativeController dismissKeyboard];
 
   // Ensure that voice search objects are created.
   [self ensureVoiceSearchControllerCreated];
@@ -4962,9 +4959,6 @@ bubblePresenterForFeature:(const base::Feature&)feature
   [self.dispatcher cancelOmniboxEdit];
   // Dismiss the soft keyboard (if open).
   [_model.currentTab.view endEditing:NO];
-  id nativeController = [self nativeControllerForTab:_model.currentTab];
-  if ([nativeController respondsToSelector:@selector(dismissKeyboard)])
-    [nativeController dismissKeyboard];
   // Dismiss Find in Page focus.
   [self updateFindBar:NO shouldFocus:NO];
 

ios/web/public/web_state/ui/crw_native_content.h

@@ -61,9 +61,6 @@ struct ContextMenuParams;
 // not exist in the web/ layer.
 - (BOOL)wantsLocationBarHintText;
 
-// Dismisses on-screen keyboard if necessary.
-- (void)dismissKeyboard;
-
 // Dismisses any outstanding modal interaction elements (e.g. modal view
 // controllers, context menus, etc).
 - (void)dismissModals;