Adds a test for setting empty composition text.

ui/base/ime/dummy_text_input_client.h

Index: ui/base/ime/dummy_text_input_client.h
diff --git a/ui/base/ime/dummy_text_input_client.h b/ui/base/ime/dummy_text_input_client.h
index 41c65e4a51293dc9e8164c5f3dc27a3eba3639ea..6b78aab359bcf5197b868cef84bde90d69512f5e 100644
--- a/ui/base/ime/dummy_text_input_client.h
+++ b/ui/base/ime/dummy_text_input_client.h
@@ -52,10 +52,12 @@ class DummyTextInputClient : public TextInputClient {
 
   int insert_char_count() const { return insert_char_count_; }
   base::char16 last_insert_char() const { return last_insert_char_; }
-  int insert_text_count() const { return insert_text_count_; }
-  base::string16 last_insert_text() const { return last_insert_text_; }
-  int set_composition_count() const { return set_composition_count_; }
-  const CompositionText& last_composition() const { return last_composition_; }
+  const std::vector<base::string16>& insert_text_history() const {
+    return insert_text_history_;
+  }
+  const std::vector<CompositionText>& composition_history() const {
+    return composition_history_;
+  }
 
   TextInputType text_input_type_;
 
@@ -63,11 +65,9 @@ class DummyTextInputClient : public TextInputClient {
 
  private:
   int insert_char_count_;
-  int insert_text_count_;
-  int set_composition_count_;
   base::char16 last_insert_char_;
-  base::string16 last_insert_text_;
-  CompositionText last_composition_;
+  std::vector<base::string16> insert_text_history_;
+  std::vector<CompositionText> composition_history_;
 };
 
 }  // namespace ui