Implement chrome.input.ime.setComposition/commitText API.

chrome/browser/ui/input_method/input_method_engine.h

Index: chrome/browser/ui/input_method/input_method_engine.h
diff --git a/chrome/browser/ui/input_method/input_method_engine.h b/chrome/browser/ui/input_method/input_method_engine.h
index 273213d3939017f47ee121ccb20591a137dab748..e1e03a38a9678a067916ca82418a699b92943e6f 100644
--- a/chrome/browser/ui/input_method/input_method_engine.h
+++ b/chrome/browser/ui/input_method/input_method_engine.h
@@ -24,6 +24,12 @@ class InputMethodEngine : public InputMethodEngineBase {
   std::string GetExtensionId() const override;
 
  private:
+  // input_method::InputMethodEngineBase:
+  void UpdateComposition(const ui::CompositionText& composition_text,
+                         uint32_t cursor_pos,
+                         bool is_visible) override;
+  void CommitTextToInputContext(int context_id, const char* text) override;
+
   DISALLOW_COPY_AND_ASSIGN(InputMethodEngine);
 };