blimp: Hook up the layer holding the tab content into Chrome.

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 c08f441a27bc696ffe3064c90ed2cbebbc5a4528..e748c365708b8a4e28a243757252707ff8a8b327 100644
--- a/blimp/client/core/contents/blimp_contents_impl.h
+++ b/blimp/client/core/contents/blimp_contents_impl.h
@@ -25,6 +25,7 @@ class BlimpContentsImplAndroid;
 #endif  // defined(OS_ANDROID)
 
 class BlimpContentsObserver;
+class BlimpContentsView;
 class BlimpNavigationController;
 class TabControlFeature;
 
@@ -43,6 +44,7 @@ class BlimpContentsImpl : public BlimpContents,
   BlimpNavigationControllerImpl& GetNavigationController() override;
   void AddObserver(BlimpContentsObserver* observer) override;
   void RemoveObserver(BlimpContentsObserver* observer) override;
+  gfx::NativeView GetNativeView() override;
 
   // Check if some observer is in the observer list.
   bool HasObserver(BlimpContentsObserver* observer);
@@ -73,6 +75,10 @@ class BlimpContentsImpl : public BlimpContents,
   // feature instead of tab control feature. crbug.com/639154.
   TabControlFeature* tab_control_feature_ = nullptr;
 
+  // The BlimpContentsView abstracts the platform specific view system details
+  // from the BlimpContents.
+  std::unique_ptr<BlimpContentsView> blimp_contents_view_;
+
   DISALLOW_COPY_AND_ASSIGN(BlimpContentsImpl);
 };