Implement cc::FilterOperations::MapRect.

cc/output/filter_operations.h

 // 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.
 
 #ifndef CC_OUTPUT_FILTER_OPERATIONS_H_
 #define CC_OUTPUT_FILTER_OPERATIONS_H_
 
 #include <stddef.h>
 
 #include <vector>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/output/filter_operation.h"
 
 namespace base {
 namespace trace_event {
 class TracedValue;
 }
 class Value;
 }
 
+namespace gfx {
+class Rect;
+}
+
 namespace cc {
 
 // An ordered list of filter operations.
 class CC_EXPORT FilterOperations {
  public:
   FilterOperations();
 
   FilterOperations(const FilterOperations& other);
 
   ~FilterOperations();
 
   FilterOperations& operator=(const FilterOperations& other);
 
   bool operator==(const FilterOperations& other) const;
 
   bool operator!=(const FilterOperations& other) const {
     return !(*this == other);
   }
 
   void Append(const FilterOperation& filter);
 
   // Removes all filter operations.
   void Clear();
 
   bool IsEmpty() const;
 
+  // Maps "forward" to determine which pixels in a destination rect are affected
+  // by pixels in the source rect.
+  gfx::Rect MapRect(const gfx::Rect& rect) const;
+
   void GetOutsets(int* top, int* right, int* bottom, int* left) const;

[Stephen White, 2016/04/11 18:05:00]

Do we still need this?

[jbroman, 2016/04/11 20:21:52]

Yes. None of the call sites have been rewritten yet; all of them will need to be
to delete this.

   bool HasFilterThatMovesPixels() const;
   bool HasFilterThatAffectsOpacity() const;
   bool HasReferenceFilter() const;
 
   size_t size() const {
     return operations_.size();
   }
 
   const FilterOperation& at(size_t index) const {
     DCHECK_LT(index, size());
@@ skipping 14 matching lines @@
 
   void AsValueInto(base::trace_event::TracedValue* value) const;
 
  private:
   std::vector<FilterOperation> operations_;
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_FILTER_OPERATIONS_H_