Fixed guestview sizing bug that resulted in incorrect <webview> sizing on the signin page.

extensions/browser/guest_view/guest_view_base.h

Index: extensions/browser/guest_view/guest_view_base.h
diff --git a/extensions/browser/guest_view/guest_view_base.h b/extensions/browser/guest_view/guest_view_base.h
index ef3d8559e86bd92a999279ece850098989901f44..3024d2f5ff224f0998ced1e2226de679db23691b 100644
--- a/extensions/browser/guest_view/guest_view_base.h
+++ b/extensions/browser/guest_view/guest_view_base.h
@@ -340,6 +340,23 @@ class GuestViewBase : public content::BrowserPluginGuestDelegate,
   void DispatchOnResizeEvent(const gfx::Size& old_size,
                              const gfx::Size& new_size);
 
+  // Get the zoom factor for the embedder's web contents.
+  double GetEmbedderZoomFactor();
+
+  // Convert sizes in pixels from logical to physical numbers of pixels.
+  // Note that a size can consist of a fractional number of logical pixels
+  // (hence |logical_pixels| is represented as a double), but will always
+  // consist of an integral number of physical pixels (hence the return value
+  // is represented as an int).
+  int LogicalPixelsToPhysicalPixels(double logical_pixels);
+
+  // Convert sizes in pixels from physical to logical numbers of pixels.
+  // Note that a size can consist of a fractional number of logical pixels
+  // (hence the return value is represented as a double), but will always
+  // consist of an integral number of physical pixels (hence |physical_pixels|
+  // is represented as an int).
+  double PhysicalPixelsToLogicalPixels(int physical_pixels);
+
   void SetUpSizing(const base::DictionaryValue& params);
 
   void StartTrackingEmbedderZoomLevel();