Remove WebContents::InsertCSS since it is unused

content/browser/web_contents/web_contents_android.h

 // Copyright 2013 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 CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_ANDROID_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_ANDROID_H_
 
 #include <jni.h>
 
 #include <memory>
@@ skipping 99 matching lines @@
   void ScrollFocusedEditableNodeIntoView(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& obj);
   void SelectWordAroundCaret(JNIEnv* env,
                              const base::android::JavaParamRef<jobject>& obj);
   void AdjustSelectionByCharacterOffset(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& obj,
       jint start_adjust,
       jint end_adjust);
-  void InsertCSS(JNIEnv* env,
-                 const base::android::JavaParamRef<jobject>& jobj,
-                 const base::android::JavaParamRef<jstring>& jcss);
   void EvaluateJavaScript(JNIEnv* env,
                           const base::android::JavaParamRef<jobject>& obj,
                           const base::android::JavaParamRef<jstring>& script,
                           const base::android::JavaParamRef<jobject>& callback);
   void EvaluateJavaScriptForTests(
       JNIEnv* env,
       const base::android::JavaParamRef<jobject>& obj,
       const base::android::JavaParamRef<jstring>& script,
       const base::android::JavaParamRef<jobject>& callback);
 
@@ skipping 89 matching lines @@
   SynchronousCompositorClient* synchronous_compositor_client_;
 
   base::WeakPtrFactory<WebContentsAndroid> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsAndroid);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_ANDROID_H_