cc: Add unit tests for non-identity matrix for FilterOperation::MapRect.

cc/output/filter_operation.cc

 // Copyright 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 <stddef.h>
 
 #include <algorithm>
 
 #include "base/trace_event/trace_event_argument.h"
 #include "base/values.h"
@@ skipping 326 matching lines @@
       float spread_x = std::abs(spread.x());
       float spread_y = std::abs(spread.y());
       gfx::Rect result = rect;
       result.Inset(-spread_x, -spread_y, -spread_x, -spread_y);
       return result;
     }
     case FilterOperation::DROP_SHADOW: {
       SkVector spread = MapStdDeviation(op.amount(), matrix);
       float spread_x = std::abs(spread.x());
       float spread_y = std::abs(spread.y());
-      gfx::Rect result = rect;
+      gfx::RectF result(rect);
       result.Inset(-spread_x, -spread_y, -spread_x, -spread_y);
 
-      gfx::Vector2d drop_shadow_offset =
-          op.drop_shadow_offset().OffsetFromOrigin();
-      if (direction == SkImageFilter::kForward_MapDirection)
-        result += drop_shadow_offset;
-      else
-        result -= drop_shadow_offset;
-
-      result.Union(rect);
-      return result;
+      gfx::Point drop_shadow_offset = op.drop_shadow_offset();
+      SkVector mapped_drop_shadow_offset;
+      matrix.mapVector(drop_shadow_offset.x(), drop_shadow_offset.y(),
+                       &mapped_drop_shadow_offset);
+      if (direction == SkImageFilter::kReverse_MapDirection)
+        mapped_drop_shadow_offset = -mapped_drop_shadow_offset;
+      result += gfx::Vector2dF(mapped_drop_shadow_offset.x(),
+                               mapped_drop_shadow_offset.y());
+      result.Union(gfx::RectF(rect));
+      return gfx::ToEnclosingRect(result);
     }
     case FilterOperation::REFERENCE: {
       if (!op.image_filter())
         return rect;
       return gfx::SkIRectToRect(op.image_filter()->filterBounds(
           gfx::RectToSkIRect(rect), matrix, direction));
     }
     default:
       return rect;
   }
 }
 
 }  // namespace
 
 gfx::Rect FilterOperation::MapRect(const gfx::Rect& rect,
                                    const SkMatrix& matrix) const {
   return MapRectInternal(*this, rect, matrix,
                          SkImageFilter::kForward_MapDirection);
 }
 
 gfx::Rect FilterOperation::MapRectReverse(const gfx::Rect& rect,
                                           const SkMatrix& matrix) const {
   return MapRectInternal(*this, rect, matrix,
                          SkImageFilter::kReverse_MapDirection);
 }
 
 }  // namespace cc