Remove unused function Compositor::setDeviceScaleFactor.

content/public/browser/android/compositor.h

Index: content/public/browser/android/compositor.h
diff --git a/content/public/browser/android/compositor.h b/content/public/browser/android/compositor.h
index 0b8cc8769dcc8d4933678c9334be9a5fa192ecd1..be022bc50498cf7faed970b281280fb86e3ddf1a 100644
--- a/content/public/browser/android/compositor.h
+++ b/content/public/browser/android/compositor.h
@@ -42,9 +42,6 @@ class CONTENT_EXPORT Compositor {
   // Attaches the layer tree.
   virtual void SetRootLayer(scoped_refptr<cc::Layer> root) = 0;
 
-  // Set the scale factor from DIP to pixel.
-  virtual void setDeviceScaleFactor(float factor) = 0;
-
   // Set the output surface bounds.
   virtual void SetWindowBounds(const gfx::Size& size) = 0;