Convert some call sites to use explicit LayoutRect->FloatRect conversion.

Source/core/frame/RootFrameViewport.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/frame/RootFrameViewport.h"
 
 #include "core/frame/FrameView.h"
 #include "core/layout/ScrollAlignment.h"
 #include "platform/geometry/DoubleRect.h"
@@ skipping 143 matching lines @@
         ScrollAlignment::getRectToExpose(viewRectInContent, rectInContent, alignX, alignY);
 
     // visualViewport.scrollIntoView will attempt to center the given rect within the viewport
     // so to prevent it from adjusting r's coordinates the rect must match the viewport's size
     // i.e. add the subtracted scrollbars from above back in.
     // FIXME: This is hacky and required because getRectToExpose doesn't naturally account
     // for the two viewports. crbug.com/449340.
     targetViewport.setSize(LayoutSize(visualViewport().visibleContentRect().size()));
 
     // Snap the visible rect to layout units to match the calculated target viewport rect.
-    FloatRect visible =
-        LayoutRect(visualViewport().scrollPositionDouble(), visualViewport().visibleContentRect().size());
+    FloatRect visible(LayoutRect(visualViewport().scrollPositionDouble(), visualViewport().visibleContentRect().size()));
 
     float centeringOffsetX = (visible.width() - targetViewport.width()) / 2;
     float centeringOffsetY = (visible.height() - targetViewport.height()) / 2;
 
     DoublePoint targetOffset(
         targetViewport.x() - centeringOffsetX,
         targetViewport.y() - centeringOffsetY);
 
     setScrollPosition(targetOffset, ProgrammaticScroll);
 
@@ skipping 160 matching lines @@
 }
 
 DEFINE_TRACE(RootFrameViewport)
 {
     visitor->trace(m_visualViewport);
     visitor->trace(m_layoutViewport);
     ScrollableArea::trace(visitor);
 }
 
 } // namespace blink