Fix DCHECK() in infobar animation.

chrome/browser/ui/views/infobars/infobar.h

Index: chrome/browser/ui/views/infobars/infobar.h
===================================================================
--- chrome/browser/ui/views/infobars/infobar.h	(revision 80169)
+++ chrome/browser/ui/views/infobars/infobar.h	(working copy)
@@ -45,9 +45,15 @@
   ui::SlideAnimation* animation() { return animation_.get(); }
   const ui::SlideAnimation* animation() const { return animation_.get(); }
 
-  // Subclasses may optionally override this.
-  virtual void PlatformSpecificHide(bool animate);
+  // Calls PlatformSpecificRecalculateHeight(), then informs our container our
+  // height has changed.
+  void RecalculateHeight();
 
+  // Platforms may optionally override these if they need to do work during
+  // processing of the given calls.
+  virtual void PlatformSpecificHide(bool animate) {}
+  virtual void PlatformSpecificRecalculateHeight() {}
+
  private:
   // ui::AnimationDelegate:
   virtual void AnimationEnded(const ui::Animation* animation) OVERRIDE;