exo: Implement v6 of touch protocol including shape and frame event

components/exo/touch.h

Index: components/exo/touch.h
diff --git a/components/exo/touch.h b/components/exo/touch.h
index 5193f782e6787d0300d562272c353326a595aba7..573b13a24c0cabd8774a99a6db570ad9ae3a9f6f 100644
--- a/components/exo/touch.h
+++ b/components/exo/touch.h
@@ -32,6 +32,12 @@ class Touch : public ui::EventHandler, public SurfaceObserver {
   void OnSurfaceDestroying(Surface* surface) override;
 
  private:
+  struct TouchDetails {
+    int id;
+    float major;
+    float minor;
+  };
+
   // Returns the effective target for |event|.
   Surface* GetEffectiveTargetForEvent(ui::Event* event) const;
 
@@ -42,7 +48,10 @@ class Touch : public ui::EventHandler, public SurfaceObserver {
   Surface* focus_ = nullptr;
 
   // Vector of touch points in focus surface.
-  std::vector<int> touch_points_;
+  std::vector<TouchDetails> touch_points_;
+
+  // Helper method to find touches of a specific id.
+  std::vector<TouchDetails>::iterator FindTouch(int id);
 
   DISALLOW_COPY_AND_ASSIGN(Touch);
 };