cc: Implement and use FilterOperations::MapRectReverse for mapping backdrop bounding box.

cc/output/filter_operations.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 "cc/output/filter_operations.h"
 
 #include <stddef.h>
 
 #include <cmath>
 #include <numeric>
@@ skipping 55 matching lines @@
 gfx::Rect FilterOperations::MapRect(const gfx::Rect& rect,
                                     const SkMatrix& matrix) const {
   auto accumulate_rect = [matrix](const gfx::Rect& rect,
                                   const FilterOperation& op) {
     return op.MapRect(rect, matrix);
   };
   return std::accumulate(operations_.begin(), operations_.end(), rect,
                          accumulate_rect);
 }
 
+gfx::Rect FilterOperations::MapRectReverse(const gfx::Rect& rect,
+                                           const SkMatrix& matrix) const {
+  auto accumulate_rect = [&matrix](const gfx::Rect& rect,
+                                   const FilterOperation& op) {
+    return op.MapRectReverse(rect, matrix);
+  };
+  return std::accumulate(operations_.rbegin(), operations_.rend(), rect,
+                         accumulate_rect);
+}
+
 void FilterOperations::GetOutsets(int* top,
                                   int* right,
                                   int* bottom,
                                   int* left) const {
   *top = *right = *bottom = *left = 0;
   for (size_t i = 0; i < operations_.size(); ++i) {
     const FilterOperation& op = operations_[i];
     // TODO(hendrikw): We should refactor some of this. See crbug.com/523534.
     if (op.type() == FilterOperation::REFERENCE) {
       if (!op.image_filter())
@@ skipping 143 matching lines @@
 void FilterOperations::AsValueInto(
     base::trace_event::TracedValue* value) const {
   for (size_t i = 0; i < operations_.size(); ++i) {
     value->BeginDictionary();
     operations_[i].AsValueInto(value);
     value->EndDictionary();
   }
 }
 
 }  // namespace cc