[Android] Suppress javascript dialogs from background tabs in custom tab

components/web_contents_delegate_android/web_contents_delegate_android.h

 // Copyright (c) 2012 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.
 
 #ifndef COMPONENTS_WEB_CONTENTS_DELEGATE_ANDROID_WEB_CONTENTS_DELEGATE_ANDROID_H_
 #define COMPONENTS_WEB_CONTENTS_DELEGATE_ANDROID_WEB_CONTENTS_DELEGATE_ANDROID_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 97 matching lines @@
       const content::WebContents* web_contents) const override;
   void ShowValidationMessage(content::WebContents* web_contents,
                              const gfx::Rect& anchor_in_root_view,
                              const base::string16& main_text,
                              const base::string16& sub_text) override;
   void HideValidationMessage(content::WebContents* web_contents) override;
   void MoveValidationMessage(content::WebContents* web_contents,
                              const gfx::Rect& anchor_in_root_view) override;
   void RequestAppBannerFromDevTools(
       content::WebContents* web_contents) override;
+  bool ShouldSuppressDialogs(content::WebContents* web_contents) override;
 
  protected:
   base::android::ScopedJavaLocalRef<jobject> GetJavaDelegate(JNIEnv* env) const;
 
  private:
   // We depend on the java side user of WebContentDelegateAndroid to hold a
   // strong reference to that object as long as they want to receive callbacks
   // on it. Using a weak ref here allows it to be correctly GCed.
   JavaObjectWeakGlobalRef weak_java_delegate_;
 
   std::unique_ptr<ValidationMessageBubbleAndroid> validation_message_bubble_;
 };
 
 }  // namespace web_contents_delegate_android
 
 #endif  // COMPONENTS_WEB_CONTENTS_DELEGATE_ANDROID_WEB_CONTENTS_DELEGATE_ANDROID_H_