Move SkRecordComputeLayers and CollectLayers into SkRecordDraw.cpp

tests/PictureTest.cpp

Index: tests/PictureTest.cpp
diff --git a/tests/PictureTest.cpp b/tests/PictureTest.cpp
index 42bd25806c7ca85561e230ebf2e3ff8e438d7aeb..3cb145e7a4822019b5158b628ea76fca3e4806a3 100644
--- a/tests/PictureTest.cpp
+++ b/tests/PictureTest.cpp
@@ -1018,11 +1018,12 @@ static void test_gpu_picture_optimization(skiatest::Reporter* reporter,
             REPORTER_ASSERT(reporter, !info0.fIsNested && !info0.fHasNestedLayers);
 
             REPORTER_ASSERT(reporter, NULL == info1.fPicture);
-            REPORTER_ASSERT(reporter, kWidth == info1.fBounds.width() &&
-                                      kHeight == info1.fBounds.height());
+            REPORTER_ASSERT(reporter, kWidth/2.0 == info1.fBounds.width() &&
+                                      kHeight/2.0 == info1.fBounds.height());
             REPORTER_ASSERT(reporter, info1.fLocalMat.isIdentity());
             REPORTER_ASSERT(reporter, info1.fPreMat.isIdentity());
-            REPORTER_ASSERT(reporter, 0 == info1.fBounds.fLeft && 0 == info1.fBounds.fTop);
+            REPORTER_ASSERT(reporter, kWidth/2.0 == info1.fBounds.fLeft && 
+                                      kHeight/2.0 == info1.fBounds.fTop);
             REPORTER_ASSERT(reporter, NULL == info1.fPaint);
             REPORTER_ASSERT(reporter, !info1.fIsNested &&
                                       info1.fHasNestedLayers); // has a nested SL