Windows: Fix opacity of drag images....

gfx/skbitmap_operations_unittest.cc

 // Copyright (c) 2009 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 "gfx/skbitmap_operations.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkColorPriv.h"
 #include "third_party/skia/include/core/SkUnPreMultiply.h"
@@ skipping 453 matching lines @@
   // Test multiple steps of downsampling.
   SkBitmap large;
   large.setConfig(SkBitmap::kARGB_8888_Config, 100, 43);
   large.allocPixels();
   result = SkBitmapOperations::DownsampleByTwoUntilSize(large, 6, 6);
 
   // The result should be divided in half 100x43 -> 50x22 -> 25x11
   EXPECT_EQ(25, result.width());
   EXPECT_EQ(11, result.height());
 }
+
+TEST(SkBitmapOperationsTest, UnPreMultiply) {
+  SkBitmap input;
+  input.setConfig(SkBitmap::kARGB_8888_Config, 2, 2);
+  input.allocPixels();
+
+  *input.getAddr32(0, 0) = 0x80000000;
+  *input.getAddr32(1, 0) = 0x80808080;
+  *input.getAddr32(0, 1) = 0xFF00CC88;
+  *input.getAddr32(1, 1) = 0x0000CC88;
+
+  SkBitmap result = SkBitmapOperations::UnPreMultiply(input);
+  EXPECT_EQ(2, result.width());
+  EXPECT_EQ(2, result.height());
+
+  SkAutoLockPixels lock(result);
+  EXPECT_EQ(0x80000000, *result.getAddr32(0, 0));
+  EXPECT_EQ(0x80FFFFFF, *result.getAddr32(1, 0));
+  EXPECT_EQ(0xFF00CC88, *result.getAddr32(0, 1));
+  EXPECT_EQ(0x00000000u, *result.getAddr32(1, 1));  // "Division by zero".
+}