Update SrcRectConstraint doc

include/core/SkCanvas.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCanvas_DEFINED
 #define SkCanvas_DEFINED
 
@@ skipping 787 matching lines @@
     enum SrcRectConstraint {
         /**
          *  If kStrict is specified, the implementation must respect the src-rect
          *  (if specified) strictly, and will never sample outside of those bounds during sampling
          *  even when filtering. This may be slower than kFast.
          */
         kStrict_SrcRectConstraint,
 
         /**
          *  If kFast is specified, the implementation may sample outside of the src-rect
-         *  (if specified) by at most 1 pixel when filtering. This allows greater flexibility
+         *  (if specified) by half the width of filter. This allows greater flexibility
          *  to the implementation and can make the draw much faster.
          */
         kFast_SrcRectConstraint,
     };
 
     /** Draw the specified image, scaling and translating so that it fills the specified
      *  dst rect. If the src rect is non-null, only that subset of the image is transformed
      *  and drawn.
      *
      *  @param image      The image to be drawn
@@ skipping 59 matching lines @@
      *                    bitmap will be drawn
      *  @param paint      The paint used to draw the bitmap, or NULL
      *  @param constraint Control the tradeoff between speed and exactness w.r.t. the src-rect.
      */
     void drawBitmapRect(const SkBitmap& bitmap, const SkRect& src, const SkRect& dst,
                         const SkPaint* paint, SrcRectConstraint = kStrict_SrcRectConstraint);
     // variant where src is SkIRect
     void drawBitmapRect(const SkBitmap& bitmap, const SkIRect& isrc, const SkRect& dst,
                         const SkPaint* paint, SrcRectConstraint = kStrict_SrcRectConstraint);
     void drawBitmapRect(const SkBitmap& bitmap, const SkRect& dst, const SkPaint* paint,
-                       SrcRectConstraint = kStrict_SrcRectConstraint);
+                        SrcRectConstraint = kStrict_SrcRectConstraint);
 
     /**
      *  Draw the bitmap stretched differentially to fit into dst.
      *  center is a rect within the bitmap, and logically divides the bitmap
      *  into 9 sections (3x3). For example, if the middle pixel of a [5x5]
      *  bitmap is the "center", then the center-rect should be [2, 2, 3, 3].
      *
      *  If the dst is >= the bitmap size, then...
      *  - The 4 corners are not stretched at all.
      *  - The sides are stretched in only one axis.
@@ skipping 662 matching lines @@
 
 class SkCanvasClipVisitor {
 public:
     virtual ~SkCanvasClipVisitor();
     virtual void clipRect(const SkRect&, SkRegion::Op, bool antialias) = 0;
     virtual void clipRRect(const SkRRect&, SkRegion::Op, bool antialias) = 0;
     virtual void clipPath(const SkPath&, SkRegion::Op, bool antialias) = 0;
 };
 
 #endif