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

ui/android/junit/src/org/chromium/ui/base/SelectFileDialogTest.java

Index: ui/android/junit/src/org/chromium/ui/base/SelectFileDialogTest.java
diff --git a/ui/android/junit/src/org/chromium/ui/base/SelectFileDialogTest.java b/ui/android/junit/src/org/chromium/ui/base/SelectFileDialogTest.java
index fac9e831bb0733963248d80acdc3789f9703fa2f..10c662363db95c0d0cc1bdc51ada266ef9da760e 100644
--- a/ui/android/junit/src/org/chromium/ui/base/SelectFileDialogTest.java
+++ b/ui/android/junit/src/org/chromium/ui/base/SelectFileDialogTest.java
@@ -106,6 +106,7 @@ public class SelectFileDialogTest {
         // Unknown extension, expect default response:
         assertEquals("application/octet-stream", SelectFileDialog.ensureMimeType(".flv"));
 
+        assertEquals(null, SelectFileDialog.convertToImageMimeTypes(new ArrayList<>()));
         assertEquals(null, SelectFileDialog.convertToImageMimeTypes(Arrays.asList("")));
         assertEquals(null, SelectFileDialog.convertToImageMimeTypes(Arrays.asList("foo/bar")));
         assertEquals(Arrays.asList("image/jpeg"),