Revert of Made top controls work with virtual viewport pinch-to-zoom. (Blink)

Source/core/frame/PinchViewport.h

Index: Source/core/frame/PinchViewport.h
diff --git a/Source/core/frame/PinchViewport.h b/Source/core/frame/PinchViewport.h
index 03e844973c7473abefbf17c62063e042628d8e7b..4ab3a0246d63e1fb369b94916424311e8128b66a 100644
--- a/Source/core/frame/PinchViewport.h
+++ b/Source/core/frame/PinchViewport.h
@@ -83,6 +83,7 @@
     FloatPoint location() const { return m_offset; }
 
     // Sets the size of the inner viewport when unscaled in CSS pixels.
+    // This will be clamped to the size of the outer viewport (the main frame).
     void setSize(const IntSize&);
     IntSize size() const { return m_size; }
 
@@ -117,14 +118,6 @@
     // scroll extents of the viewport within the document.
     IntPoint clampDocumentOffsetAtScale(const IntPoint& offset, float scale);
 
-    // FIXME: This is kind of a hack. Ideally, we would just resize the
-    // viewports to account for top controls. However, FrameView includes much
-    // more than just scrolling so we can't simply resize it without incurring
-    // all sorts of side-effects. Until we can seperate out the scrollability
-    // aspect from FrameView, we use this method to let PinchViewport make the
-    // necessary adjustments so that we don't incorrectly clamp scroll offsets
-    // coming from the compositor. crbug.com/422328
-    void setTopControlsAdjustment(float);
 private:
     // ScrollableArea implementation
     virtual bool isActive() const override { return false; }
@@ -174,7 +167,6 @@
     FloatPoint m_offset;
     float m_scale;
     IntSize m_size;
-    float m_topControlsAdjustment;
 };
 
 } // namespace blink