Remove the AA requirement for selecting GrEffect-based clipping.

src/gpu/GrClipMaskManager.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 GrClipMaskManager_DEFINED
 #define GrClipMaskManager_DEFINED
 
@@ skipping 88 matching lines @@
      */
     enum ClipMaskType {
         kNone_ClipMaskType,
         kStencil_ClipMaskType,
         kAlpha_ClipMaskType,
     } fCurrClipMaskType;
 
     GrClipMaskCache fAACache;       // cache for the AA path
 
     // Attempts to install a series of coverage effects to implement the clip. Return indicates
-    // whether the element list was successfully converted to effects.
+    // whether the element list was successfully converted to effects. One of the elements may
+    // be selected to use the scissor. If so scissorRect will be updated to a valid rectangle
+    // that the caller should set as the scissor rect. If not, scissorRect won't be modified.
     bool installClipEffects(const GrReducedClip::ElementList&,
                             GrDrawState::AutoRestoreEffects*,
                             const SkVector& clipOffset,
-                            const SkRect* devBounds);
+                            const SkRect* devBounds,
+                            SkIRect* scissorRect);
 
     // Draws the clip into the stencil buffer
     bool createStencilClipMask(int32_t elementsGenID,
                                GrReducedClip::InitialState initialState,
                                const GrReducedClip::ElementList& elements,
                                const SkIRect& clipSpaceIBounds,
                                const SkIPoint& clipSpaceToStencilOffset);
     // Creates an alpha mask of the clip. The mask is a rasterization of elements through the
     // rect specified by clipSpaceIBounds.
     GrTexture* createAlphaClipMask(int32_t elementsGenID,
@@ skipping 52 matching lines @@
      * clipping.
      */
     void adjustStencilParams(GrStencilSettings* settings,
                              StencilClipMode mode,
                              int stencilBitCnt);
 
     typedef SkNoncopyable INHERITED;
 };
 
 #endif // GrClipMaskManager_DEFINED