Close the save card bubble on tab switch.

chrome/browser/ui/autofill/save_card_bubble_controller.h

Index: chrome/browser/ui/autofill/save_card_bubble_controller.h
diff --git a/chrome/browser/ui/autofill/save_card_bubble_controller.h b/chrome/browser/ui/autofill/save_card_bubble_controller.h
index 231c9d08b6db0620f76ae4bc4904dae8f5916bf5..1dde3a38699928be554e4d6d6cd8b1e7d9e5269a 100644
--- a/chrome/browser/ui/autofill/save_card_bubble_controller.h
+++ b/chrome/browser/ui/autofill/save_card_bubble_controller.h
@@ -41,6 +41,9 @@ class SaveCardBubbleController {
   // Returns an empty string if no message should be displayed.
   virtual base::string16 GetExplanatoryMessage() const = 0;
 
+  // Hides the bubble if it is currently showing.
+  virtual void HideBubble() = 0;

[Evan Stade, 2016/01/12 00:29:00]

doesn't need to be here, SaveCardBubbleView doesn't use it and the one callsite
is a SaveCardBubbleControllerImpl instance.

[Justin Donnelly, 2016/01/12 00:40:39]

Done.

+
   // Interaction.
   virtual void OnSaveButton() = 0;
   virtual void OnCancelButton() = 0;