Make all parameters reqiured to GrReducedClip::ReduceClipStack

src/gpu/GrReducedClip.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrReducedClip_DEFINED
 #define GrReducedClip_DEFINED
 
 #include "SkClipStack.h"
 #include "SkTLList.h"
 
 class SK_API GrReducedClip {
 public:
     typedef SkTLList<SkClipStack::Element, 16> ElementList;
 
     enum InitialState {
         kAllIn_InitialState,
         kAllOut_InitialState,
     };
 
     /**
      * This function takes a clip stack and a query rectangle and it produces a
      * reduced set of SkClipStack::Elements that are equivalent to applying the
      * full stack to the rectangle. The clip stack generation id that represents
      * the list of elements is returned in resultGenID. The initial state of the
      * query rectangle before the first clip element is applied is returned via
-     * initialState. Optionally, the caller can request a tighter bounds on the
-     * clip be returned via tighterBounds. If not nullptr, tighterBounds will
-     * always be contained by queryBounds after return. If tighterBounds is
-     * specified then it is assumed that the caller will implicitly clip against
-     * it. If the caller specifies non-nullptr for requiresAA then it will indicate
-     * whether anti-aliasing is required to process any of the elements in the
-     * result.
-     *
-     * This may become a member function of SkClipStack when its interface is
-     * determined to be stable.
+     * initialState. The reducer output tighterBounds is a tighter bounds on the
+     * clip. tighterBounds will always be contained by queryBounds after return.
+     * It is assumed that the caller will not draw outside of tighterBounds.
+     * The requiresAA output will indicate whether anti-aliasing is required to
+     * process any of the elements in the element list result.
      */
     static void ReduceClipStack(const SkClipStack& stack,
                                 const SkIRect& queryBounds,
                                 ElementList* result,
                                 int32_t* resultGenID,
                                 InitialState* initialState,
-                                SkIRect* tighterBounds = nullptr,
-                                bool* requiresAA = nullptr);
+                                SkIRect* tighterBounds,
+                                bool* requiresAA);
 };
 
 #endif