Migrate TabControlFeature from 0.5 to 0.6

blimp/client/core/contents/blimp_contents_impl.h

Index: blimp/client/core/contents/blimp_contents_impl.h
diff --git a/blimp/client/core/contents/blimp_contents_impl.h b/blimp/client/core/contents/blimp_contents_impl.h
index 1d91ba0d1c61321bce2f56656579a88620b9375f..b9a4cae6584042af094e2e90f95b6e13143f47e8 100644
--- a/blimp/client/core/contents/blimp_contents_impl.h
+++ b/blimp/client/core/contents/blimp_contents_impl.h
@@ -32,6 +32,7 @@ class BlimpContentsImpl : public BlimpContents,
                           public BlimpNavigationControllerDelegate {
  public:
   BlimpContentsImpl();
+  explicit BlimpContentsImpl(int id);
   ~BlimpContentsImpl() override;
 
 #if defined(OS_ANDROID)
@@ -47,6 +48,8 @@ class BlimpContentsImpl : public BlimpContents,
   // BlimpNavigationControllerDelegate implementation.
   void NotifyURLLoaded(const GURL& url) override;
 
+  int id() { return id_; }
+
  private:
   // Handles the back/forward list and loading URLs.
   BlimpNavigationControllerImpl navigation_controller_;
@@ -54,6 +57,8 @@ class BlimpContentsImpl : public BlimpContents,
   // A list of all the observers of this BlimpContentsImpl.
   base::ObserverList<BlimpContentsObserver> observers_;
 
+  int id_;
+
   DISALLOW_COPY_AND_ASSIGN(BlimpContentsImpl);
 };