ui: Make gfx::Size::Scale() mutate the class. Add gfx::ScaleSize() similar to Rect/Point.

cc/layer_tree_host_impl_unittest.cc

 // Copyright 2011 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 "cc/layer_tree_host_impl.h"
 
 #include <cmath>
 
@@ skipping 469 matching lines @@
     // This point is still inside the non-fast region.
     EXPECT_EQ(m_hostImpl->scrollBegin(gfx::Point(10, 10), InputHandlerClient::Wheel), InputHandlerClient::ScrollOnMainThread);
 }
 
 TEST_P(LayerTreeHostImplTest, maxScrollOffsetChangedByDeviceScaleFactor)
 {
     setupScrollAndContentsLayers(gfx::Size(100, 100));
 
     float deviceScaleFactor = 2;
     gfx::Size layoutViewport(25, 25);
-    gfx::Size deviceViewport(gfx::ToFlooredSize(layoutViewport.Scale(deviceScaleFactor)));
+    gfx::Size deviceViewport(gfx::ToFlooredSize(gfx::ScaleSize(layoutViewport, deviceScaleFactor)));
     m_hostImpl->setViewportSize(layoutViewport, deviceViewport);
     m_hostImpl->setDeviceScaleFactor(deviceScaleFactor);
     EXPECT_EQ(m_hostImpl->rootLayer()->maxScrollOffset(), gfx::Vector2d(25, 25));
 
     deviceScaleFactor = 1;
     m_hostImpl->setViewportSize(layoutViewport, layoutViewport);
     m_hostImpl->setDeviceScaleFactor(deviceScaleFactor);
     EXPECT_EQ(m_hostImpl->rootLayer()->maxScrollOffset(), gfx::Vector2d(75, 75));
 }
 
@@ skipping 3935 matching lines @@
         verifyRenderPassTestData(removeRenderPassesCases[testCaseIndex], testData);
         testCaseIndex++;
     }
 }
 
 INSTANTIATE_TEST_CASE_P(LayerTreeHostImplTests,
                         LayerTreeHostImplTest,
                         ::testing::Values(false, true));
 
 }  // anonymous namespace