Update SkLightingShader to support rotation

src/effects/SkLightingShader.h

-
-/*
- * Copyright 2015 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-
-#ifndef SkLightingShader_DEFINED
-#define SkLightingShader_DEFINED
-
-#include "SkPoint3.h"
-#include "SkShader.h"
-
-class SK_API SkLightingShader {
-public:
-    struct Light {
-        SkVector3   fDirection;       // direction towards the light (+Z is out of the screen).
-                                      // If degenerate, it will be replaced with (0, 0, 1).
-        SkColor3f   fColor;           // linear (unpremul) color. Range is 0..1 in each channel.
-    };
-
-    /** Returns a shader that lights the diffuse and normal maps with a single light.
-
-        It returns a shader with a reference count of 1.
-        The caller should decrement the shader's reference count when done with the shader.
-        It is an error for count to be < 2.
-        @param  diffuse     the diffuse bitmap
-        @param  normal      the normal map
-        @param  light       the light applied to the normal map
-        @param  ambient     the linear (unpremul) ambient light color. Range is 0..1/channel.
-        @param  localMatrix the matrix mapping the textures to the dest rect 
-
-        NULL will be returned if:
-            either 'diffuse' or 'normal' are empty
-            either 'diffuse' or 'normal' are too big (> 65535 on a side)
-            'diffuse' and 'normal' aren't the same size
-
-        The lighting equation is currently:
-            result = LightColor * DiffuseColor * (Normal * LightDir) + AmbientColor
-
-        The normal map is currently assumed to be an 8888 image where the normal at a texel
-        is retrieved by:
-            N.x = R-127;
-            N.y = G-127;
-            N.z = B-127;
-            N.normalize();
-        The +Z axis is thus encoded in RGB as (127, 127, 255) while the -Z axis is
-        (127, 127, 0).
-    */
-    static SkShader* Create(const SkBitmap& diffuse, const SkBitmap& normal,
-                            const SkLightingShader::Light& light, const SkColor3f& ambient,
-                            const SkMatrix* localMatrix);
-
-    SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()
-};
-
-#endif