gfx: Fix ToEnclosing/ToEnclosed math to deal with big numbers.

ui/gfx/geometry/rect_unittest.cc

 // Copyright (c) 2013 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 <limits>
 
 #include "base/basictypes.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/rect_conversions.h"
@@ skipping 892 matching lines @@
   EXPECT_FLOAT_EQ(
       0.0f, f.ManhattanInternalDistance(gfx::RectF(-1.0f, 0.0f, 1.1f, 1.0f)));
   EXPECT_FLOAT_EQ(
       0.1f + kEpsilon,
       f.ManhattanInternalDistance(gfx::RectF(-1.5f, 0.0f, 1.4f, 1.0f)));
   EXPECT_FLOAT_EQ(
       kEpsilon,
       f.ManhattanInternalDistance(gfx::RectF(-1.5f, 0.0f, 1.5f, 1.0f)));
 }
 
+TEST(RectTest, SafelyScaleToEnclosingRect) {
+  {
+    Rect input(1, 2, 3, 4);
+    Rect result = SafelyScaleToEnclosingRect(input, 5.f);
+    EXPECT_EQ(Rect(5, 10, 15, 20), result);
+  }
+  {
+    Rect input(-1, -2, 3, 4);
+    Rect result = SafelyScaleToEnclosingRect(input, 0.5f);
+    EXPECT_EQ(Rect(-1, -1, 2, 2), result);
+  }
+  {
+    Rect input(0, 0, std::numeric_limits<int>::max() / 2,
+               std::numeric_limits<int>::max());
+    Rect result = SafelyScaleToEnclosingRect(input, 2.f);
+    EXPECT_EQ(Rect(0, 0, std::numeric_limits<int>::max(),
+                   std::numeric_limits<int>::max()),
+              result);
+  }
+  {
+    Rect input(std::numeric_limits<int>::min() / 2,
+               std::numeric_limits<int>::min() / 2,
+               std::numeric_limits<int>::max(),
+               std::numeric_limits<int>::max());
+    Rect result = SafelyScaleToEnclosingRect(input, 2.f);
+    EXPECT_EQ(
+        Rect(std::numeric_limits<int>::min(), std::numeric_limits<int>::min(),
+             std::numeric_limits<int>::max(), std::numeric_limits<int>::max()),
+        result);
+  }
+  {
+    Rect input(std::numeric_limits<int>::max() / 2,
+               std::numeric_limits<int>::max() / 2,
+               std::numeric_limits<int>::max(),
+               std::numeric_limits<int>::max());
+    Rect result = SafelyScaleToEnclosingRect(input, 2.f);
+    EXPECT_EQ(Rect(std::numeric_limits<int>::max(),
+                   std::numeric_limits<int>::max(), 0, 0),
+              result);
+  }
+}
+
+
 }  // namespace gfx