Add "Paste as plain text" into text selection toolbar overflow

content/browser/web_contents/web_contents_android.cc

Index: content/browser/web_contents/web_contents_android.cc
diff --git a/content/browser/web_contents/web_contents_android.cc b/content/browser/web_contents/web_contents_android.cc
index 111773b0be67ace0112dd94124b5d1ebc9c99c69..824e15fe3b24710fed1844f666a3e1edb1503e34 100644
--- a/content/browser/web_contents/web_contents_android.cc
+++ b/content/browser/web_contents/web_contents_android.cc
@@ -272,6 +272,11 @@ void WebContentsAndroid::Paste(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   web_contents_->Paste();
 }
 
+void WebContentsAndroid::PasteAsPlainText(JNIEnv* env,
+                                          const JavaParamRef<jobject>& obj) {
+  web_contents_->PasteAndMatchStyle();

[boliu, 2017/05/02 17:31:57]

why does this method sound like the exact opposite of what we are trying to do?
even the content API isn't documented :( maybe I'm not understanding this
feature correctly..

Oh I see the explanation on the bug. add that comment here please

[Shimi Zhang, 2017/05/03 00:37:17]

Done.

+}
+
 void WebContentsAndroid::Replace(JNIEnv* env,
                                  const JavaParamRef<jobject>& obj,
                                  const JavaParamRef<jstring>& jstr) {