Fix a crash where the dragged content does not contain any text.

content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java

Index: content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
index a51110d451798cc0ac9233aaa9913c8405a96a60..422113500a938b4a4dfd4a1e65fc408c6818bea8 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
@@ -3170,7 +3170,8 @@ public class ContentViewCore implements AccessibilityStateChangeListener, Displa
 
         if (event.getAction() == DragEvent.ACTION_DRAG_STARTED) {
             // TODO(hush): support dragging more than just text.
-            return mimeTypes.length > 0 && nativeIsTouchDragDropEnabled(mNativeContentViewCore);
+            return mimeTypes != null && mimeTypes.length > 0
+                    && nativeIsTouchDragDropEnabled(mNativeContentViewCore);
         }
 
         StringBuilder content = new StringBuilder("");