Photo Picker dialog: Don't show when no accept tags are specified.

ui/android/java/src/org/chromium/ui/base/SelectFileDialog.java

Index: ui/android/java/src/org/chromium/ui/base/SelectFileDialog.java
diff --git a/ui/android/java/src/org/chromium/ui/base/SelectFileDialog.java b/ui/android/java/src/org/chromium/ui/base/SelectFileDialog.java
index c82004f5b04433f9460b7dbf9a50575315f7753b..508eebc809edbd694172cc8eb334a238cfa83417 100644
--- a/ui/android/java/src/org/chromium/ui/base/SelectFileDialog.java
+++ b/ui/android/java/src/org/chromium/ui/base/SelectFileDialog.java
@@ -282,6 +282,7 @@ public class SelectFileDialog implements WindowAndroid.IntentCallback,
      */
     @VisibleForTesting
     public static List<String> convertToImageMimeTypes(List<String> fileTypes) {
+        if (fileTypes.size() == 0) return null;
         List<String> mimeTypes = new ArrayList<>();
         for (String type : fileTypes) {
             String mimeType = ensureMimeType(type);