Add TabControlFeature to BlimpClientContextImpl

blimp/client/public/contents/blimp_contents.h

Index: blimp/client/public/contents/blimp_contents.h
diff --git a/blimp/client/public/contents/blimp_contents.h b/blimp/client/public/contents/blimp_contents.h
index ea11aa7305a00239917de041d3f01b50c2fd34d8..f91165ce6635ac5264b23c43507f1c8f1b1eb055 100644
--- a/blimp/client/public/contents/blimp_contents.h
+++ b/blimp/client/public/contents/blimp_contents.h
@@ -7,6 +7,7 @@
 
 #include "base/macros.h"
 #include "base/supports_user_data.h"
+#include "ui/gfx/geometry/size.h"
 #include "url/gurl.h"
 
 namespace blimp {
@@ -31,6 +32,11 @@ class BlimpContents : public base::SupportsUserData {
   virtual void AddObserver(BlimpContentsObserver* observer) = 0;
   virtual void RemoveObserver(BlimpContentsObserver* observer) = 0;
 
+  // Pushes the size and scale information to the engine, which will affect the
+  // web content display area for all tabs.
+  virtual void SetSizeAndScale(const gfx::Size& size,

[nyquist, 2016/08/16 20:41:04]

Could this possibly be moved to the impl instead? I think size and scale can
come from the BlimpView. If so, remember to move the comment over.

[Menglin, 2016/08/16 21:10:09]

impl has this function now. it overrides this the virtual function here. If we
only need to call it on BlimpContentsImpl, i can remove the virtual function
from here

[nyquist, 2016/08/16 21:41:40]

yeah, you should be able to do that.

[Menglin, 2016/08/17 19:48:46]

Done.

+                               float device_pixel_ratio) = 0;
+
  protected:
   BlimpContents() {}