Update SkLightingShader to support rotation

gyp/SampleApp.gyp

Index: gyp/SampleApp.gyp
diff --git a/gyp/SampleApp.gyp b/gyp/SampleApp.gyp
index f2301db7d263f38a8ad026cb8334c7df40e138f2..dd697b7c39a252f659b95e6cc707157dd599ae1c 100644
--- a/gyp/SampleApp.gyp
+++ b/gyp/SampleApp.gyp
@@ -84,7 +84,7 @@
         '../samplecode/SampleLayerMask.cpp',
         '../samplecode/SampleLayers.cpp',
         '../samplecode/SampleLCD.cpp',
-	'../samplecode/SampleLighting.cpp',
+        '../samplecode/SampleLighting.cpp',
         '../samplecode/SampleLines.cpp',
         '../samplecode/SampleLua.cpp',
         '../samplecode/SampleManyRects.cpp',
@@ -245,9 +245,9 @@
             'android_deps.gyp:Android_SampleApp',
           ],
         }],
-	[ 'skia_os == "chromeos"', {
-	  'sources!': [
-	    '../samplecode/SampleLighting.cpp',  #doesn't compile due to gpu dependencies
+        [ 'skia_os == "chromeos"', {
+          'sources!': [
+            '../samplecode/SampleLighting.cpp',  #doesn't compile due to gpu dependencies
           ],
         }],
         [ 'skia_gpu == 1', {