Scale scrollbar in use-zoom-for-dsf mode

third_party/WebKit/Source/platform/scroll/ScrollbarThemeNonMacCommon.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2008, 2009 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 12 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "platform/scroll/ScrollbarThemeNonMacCommon.h"
 
 #include "platform/PlatformMouseEvent.h"
 #include "platform/graphics/GraphicsContextStateSaver.h"
 #include "platform/graphics/paint/DrawingRecorder.h"
 #include "platform/scroll/ScrollableArea.h"
-#include "platform/scroll/ScrollbarThemeClient.h"
 
 namespace blink {
 
 bool ScrollbarThemeNonMacCommon::hasThumb(const ScrollbarThemeClient& scrollbar)
 {
     // This method is just called as a paint-time optimization to see if
     // painting the thumb can be skipped. We don't have to be exact here.
     return thumbLength(scrollbar) > 0;
 }
 
@@ skipping 22 matching lines @@
         x = scrollbar.x();
         y = scrollbar.y() + scrollbar.height() - size.height();
     }
     return IntRect(x, y, size.width(), size.height());
 }
 
 IntRect ScrollbarThemeNonMacCommon::trackRect(const ScrollbarThemeClient& scrollbar, bool)
 {
     // The track occupies all space between the two buttons.
     IntSize bs = buttonSize(scrollbar);
-    int thickness = scrollbarThickness(scrollbar.controlSize());

[skobes, 2016/01/07 21:49:10]

The other caller of ScrollbarThemeClient::controlSize is
ScrollbarTheme::minimumThumbLength.  Does that need updating as well?

[oshima, 2016/01/09 00:58:39]

Other uses seems to be for custom scrollbars, which gets scaled properly when
zoomed.

+    int thickness;
     if (scrollbar.orientation() == HorizontalScrollbar) {
+        thickness = scrollbar.height();
         if (scrollbar.width() <= 2 * bs.width())
             return IntRect();
         return IntRect(scrollbar.x() + bs.width(), scrollbar.y(), scrollbar.width() - 2 * bs.width(), thickness);
+    } else {

[skobes, 2016/01/07 21:49:10]

Remove the "else" since we return in the if block.

[oshima, 2016/01/09 00:58:39]

Done.

+        thickness = scrollbar.width();
     }
     if (scrollbar.height() <= 2 * bs.height())
         return IntRect();
     return IntRect(scrollbar.x(), scrollbar.y() + bs.height(), thickness, scrollbar.height() - 2 * bs.height());
 }
 
 void ScrollbarThemeNonMacCommon::paintTrackBackground(GraphicsContext& context, const ScrollbarThemeClient& scrollbar, const IntRect& rect)
 {
     // Just assume a forward track part. We only paint the track as a single piece when there is no thumb.
     if (!hasThumb(scrollbar))
@@ skipping 30 matching lines @@
 
         FloatRect tickRect(rect.x(), yPos, rect.width(), 3);
         context.fillRect(tickRect, Color(0xCC, 0xAA, 0x00, 0xFF));
 
         FloatRect tickStroke(rect.x(), yPos + 1, rect.width(), 1);
         context.fillRect(tickStroke, Color(0xFF, 0xDD, 0x00, 0xFF));
     }
 }
 
 } // namespace blink