Update WM shadows for MD.

ui/gfx/shadow_value.h

 // 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.
 
 #ifndef UI_GFX_SHADOW_VALUE_H_
 #define UI_GFX_SHADOW_VALUE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 23 matching lines @@
   SkColor color() const { return color_; }
 
   ShadowValue Scale(float scale) const;
 
   std::string ToString() const;
 
   // Gets margin space needed for shadows. Note that values in returned Insets
   // are negative because shadow margins are outside a boundary.
   static Insets GetMargin(const ShadowValues& shadows);
 
+  // Gets the area inside a rectangle that would be affected by shadow blur.
+  // This is similar to the margin except it's positive (the blur region is
+  // inside a hypothetical rectangle) and it accounts for the blur both inside
+  // and outside the bounding box. The region inside the "blur region" would be
+  // a uniform color.
+  static Insets GetBlurRegion(const ShadowValues& shadows);
+
  private:
   gfx::Vector2d offset_;
 
   // Blur amount of the shadow in pixels. If underlying implementation supports
   // (e.g. Skia), it can have fraction part such as 0.5 pixel. The value
   // defines a range from full shadow color at the start point inside the
   // shadow to fully transparent at the end point outside it. The range is
   // perpendicular to and centered on the shadow edge. For example, a blur
   // amount of 4.0 means to have a blurry shadow edge of 4 pixels that
   // transitions from full shadow color to fully transparent and with 2 pixels
   // inside the shadow and 2 pixels goes beyond the edge.
   double blur_;
 
   SkColor color_;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_SHADOW_VALUE_H_