Android should be able to copy HTML snippets to the system clipboard.

ui/base/clipboard/clipboard_android.cc

 // 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.
 
 #include "ui/base/clipboard/clipboard.h"
 
 #include "base/android/jni_string.h"
 #include "base/lazy_instance.h"
 #include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 83 matching lines @@
   JNIEnv* env = AttachCurrentThread();
   base::AutoLock lock(lock_);
   SyncWithAndroidClipboard();
 
   map_[format] = data;
   if (format == kPlainTextFormat) {
     ScopedJavaLocalRef<jstring> str = ConvertUTF8ToJavaString(
         env, data.c_str());
     DCHECK(str.obj() && !ClearException(env));
     Java_Clipboard_setText(env, clipboard_manager_.obj(), str.obj());
+  } else if (format == kHTMLFormat) {
+    // Android's API for storing HTML content on the clipboard requires a plain-
+    // text representation to be available as well. Because of an std::map's
+    // keys being ordered, any plain-text representation will be set already.
+    if (!ContainsKey(map_, kPlainTextFormat))
+      return;
+
+    ScopedJavaLocalRef<jstring> html = ConvertUTF8ToJavaString(
+        env, data.c_str());
+    ScopedJavaLocalRef<jstring> text = ConvertUTF8ToJavaString(
+        env, map_[kPlainTextFormat].c_str());
+
+    DCHECK(html.obj() && text.obj() && !ClearException(env));
+    Java_Clipboard_setHTMLText(
+        env, clipboard_manager_.obj(), html.obj(), text.obj());

[dcheng, 2013/10/02 22:24:15]

What is the expected behavior if a JS paste handler does something like this:

function onPaste(e) {
  e.setData('text/html', '<b>Hello world!</b>');
  e.preventDefault();
}

Do we want nothing on the clipboard in that case? It seems like we still ought
to write HTML to the clipboard in that case (with empty text content as the
fallback, since that's no worse than what it would have originally been).

[Peter Beverloo, 2013/10/23 17:11:34]

That's a good question.  Pasting HTML on Android requires the plain-text
representation because the HTML API is relatively new, and not all applications
will support that.  The experience which users would get following this
suggestion is that their older apps indicate that there is data on the clipboard
(i.e. "Paste" is enabled), but when pasting data nothing happens.

We could mitigate this by implementing Android-specific behavior that if a
ScopedClipboardWriter only writes HTML data, we call some API to normalize this
to a text-only representation.  I don't know whether such an API is available,
however. 

   }
 }
 
 void ClipboardMap::Clear() {
   JNIEnv* env = AttachCurrentThread();
   base::AutoLock lock(lock_);
   map_.clear();
   Java_Clipboard_setText(env, clipboard_manager_.obj(), NULL);
 }
 
@@ skipping 294 matching lines @@
                           const char* data_data, size_t data_len) {
   g_map.Get().Set(format.data(), std::string(data_data, data_len));
 }
 
 // See clipboard_android_initialization.h for more information.
 bool RegisterClipboardAndroid(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 } // namespace ui