hidpi support for custom cursors in windows

content/common/cursors/webcursor_unittest.cc

Index: content/common/cursors/webcursor_unittest.cc
diff --git a/content/common/cursors/webcursor_unittest.cc b/content/common/cursors/webcursor_unittest.cc
index 25c236a459994d134a57bf138789b735838ac03b..1835423eed8399cbcb8e3e45ef8ad3018feb0145 100644
--- a/content/common/cursors/webcursor_unittest.cc
+++ b/content/common/cursors/webcursor_unittest.cc
@@ -2,6 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#if defined(OS_WIN)
+#include <windows.h>
+#endif
+
 #include "base/pickle.h"
 #include "content/common/cursors/webcursor.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -257,4 +261,52 @@ TEST(WebCursorTest, AlphaConversion) {
 #endif
 }
 
+#if defined(USE_AURA)
+TEST(WebCursorTest, CursorScaleFactor) {
+  gfx::Display display;
+  display.set_device_scale_factor(80.2f);
+
+  WebCursor::CursorInfo info;
+  info.image_scale_factor = 2.0f;
+
+  WebCursor cursor;
+  cursor.InitFromCursorInfo(info);
+  cursor.SetDisplayInfo(display);
+
+  EXPECT_EQ(40.1f, cursor.GetCursorScaleFactor());
+}
+#endif
+
+#if defined(OS_WIN)
+void ScaleCursor(float scaleFactor, int hotspotX, int hotspotY) {
+  gfx::Display display;
+  display.set_device_scale_factor(scaleFactor);
+
+  WebCursor::CursorInfo info;
+  info.type = WebCursorInfo::TypeCustom;
+  info.hotspot = gfx::Point(hotspotX, hotspotY);
+
+  info.custom_image = SkBitmap();
+  info.custom_image.allocN32Pixels(10, 10);
+
+  WebCursor cursor;
+  cursor.SetDisplayInfo(display);
+  cursor.InitFromCursorInfo(info);
+
+  HCURSOR windowsCursorHandle = cursor.GetPlatformCursor();
+  EXPECT_NE(nullptr, windowsCursorHandle);
+  ICONINFO windowsIconInfo;
+  EXPECT_TRUE(GetIconInfo(windowsCursorHandle, &windowsIconInfo));
+  EXPECT_FALSE(windowsIconInfo.fIcon);
+  EXPECT_EQ(static_cast<int>(scaleFactor * hotspotX), windowsIconInfo.xHotspot);

[Nico, 2015/12/17 12:04:16]

Does this intentionally not round? For the third call, scaleFactor is 1.25 and
hotspotX is 3, so the product is 3.75. Should that really be converted to 3 and
not 4?

+  EXPECT_EQ(static_cast<int>(scaleFactor * hotspotY), windowsIconInfo.yHotspot);
+}
+
+TEST(WebCursorTest, WindowsCursorScaledAtHiDpi) {
+  ScaleCursor(2.0f, 4, 6);
+  ScaleCursor(1.5f, 2, 8);
+  ScaleCursor(1.25f, 3, 7);
+}
+#endif
+
 }  // namespace content