Scale to DIPs in ppb_graphics2d_impl for proper invalidation

ui/gfx/rect.cc

 // Copyright (c) 2012 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 "ui/gfx/rect.h"
 
+#include <math.h>
+
 #if defined(OS_WIN)
 #include <windows.h>
 #elif defined(OS_MACOSX)
 #include <ApplicationServices/ApplicationServices.h>
 #elif defined(TOOLKIT_GTK)
 #include <gdk/gdk.h>
 #endif
 
 #include "base/logging.h"
 #include "base/stringprintf.h"
@@ skipping 20 matching lines @@
 Rect::Rect(const gfx::Size& size)
     : RectBaseT(size) {
 }
 
 Rect::Rect(const gfx::Point& origin, const gfx::Size& size)
     : RectBaseT(origin, size) {
 }
 
 Rect::~Rect() {}
 
+void Rect::ScaleBounds(float scale) {
+  int left = static_cast<int>(floorf(x() * scale));
+  int top = static_cast<int>(floorf(y() * scale));
+  int right = static_cast<int>(ceilf((x() + width()) * scale));
+  int bottom = static_cast<int>(ceilf((y() + height()) * scale));
+  SetRect(left, top, right - left, bottom - top);
+}
+
 #if defined(OS_WIN)
 Rect::Rect(const RECT& r)
     : RectBaseT(gfx::Point(r.left, r.top)) {
   set_width(std::abs(r.right - r.left));
   set_height(std::abs(r.bottom - r.top));
 }
 
 Rect& Rect::operator=(const RECT& r) {
   set_x(r.left);
   set_y(r.top);
@@ skipping 51 matching lines @@
 }
 #endif
 
 std::string Rect::ToString() const {
   return base::StringPrintf("%s %s",
                             origin().ToString().c_str(),
                             size().ToString().c_str());
 }
 
 }  // namespace gfx