[Android] Remove zero length composing spans.

content/public/android/java/src/org/chromium/content/browser/input/AdapterInputConnection.java

 // Copyright (c) 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.
 
 package org.chromium.content.browser.input;
 
 import com.google.common.annotations.VisibleForTesting;
 
 import android.text.Editable;
 import android.text.InputType;
@@ skipping 133 matching lines @@
         }
 
         if (prevSelectionStart == selectionStart && prevSelectionEnd == selectionEnd
                 && prevCompositionStart == compositionStart
                 && prevCompositionEnd == compositionEnd) {
             // Nothing has changed; don't need to do anything
             return;
         }
 
         Selection.setSelection(editable, selectionStart, selectionEnd);
-        super.setComposingRegion(compositionStart, compositionEnd);
+
+        if (compositionStart == compositionEnd) {
+            removeComposingSpans(editable);
+        } else {
+            super.setComposingRegion(compositionStart, compositionEnd);
+        }
 
         if (mIgnoreTextInputStateUpdates) return;
         updateSelection(selectionStart, selectionEnd, compositionStart, compositionEnd);
     }
 
     @VisibleForTesting
     protected void updateSelection(
             int selectionStart, int selectionEnd,
             int compositionStart, int compositionEnd) {
         // Avoid sending update if we sent an exact update already previously.
@@ skipping 208 matching lines @@
     }
 
     /**
      * @see BaseInputConnection#setComposingRegion(int, int)
      */
     @Override
     public boolean setComposingRegion(int start, int end) {
         if (DEBUG) Log.w(TAG, "setComposingRegion [" + start + " " + end + "]");
         int a = Math.min(start, end);
         int b = Math.max(start, end);
-        super.setComposingRegion(a, b);
+
+        if (a == b) {
+            removeComposingSpans(getEditable());
+        } else {
+            super.setComposingRegion(a, b);
+        }
         return mImeAdapter.setComposingRegion(a, b);
     }
 
     boolean isActive() {
         return getInputMethodManagerWrapper().isActive(mInternalView);
     }
 
     public void setIgnoreTextInputStateUpdates(boolean shouldIgnore) {
         mIgnoreTextInputStateUpdates = shouldIgnore;
         if (shouldIgnore) return;
 
         Editable editable = getEditable();
         updateSelection(Selection.getSelectionStart(editable),
                 Selection.getSelectionEnd(editable),
                 getComposingSpanStart(editable),
                 getComposingSpanEnd(editable));
     }
 
     @VisibleForTesting
     protected boolean isIgnoringTextInputStateUpdates() {
         return mIgnoreTextInputStateUpdates;
     }
 
     private InputMethodManagerWrapper getInputMethodManagerWrapper() {
         return mImeAdapter.getInputMethodManagerWrapper();
     }
 }