[Reland] Relocate shaders to own dir

Consolidate all shader impls under src/shaders/.

(reland of https://skia-review.googlesource.com/c/17927/)

Change-Id: I7918bdc1aafe842ed194412ba95b9ae53a2ec1d7
Reviewed-on: https://skia-review.googlesource.com/18146
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
diff --git a/gn/core.gni b/gn/core.gni
index 50e54b8..b22ae94 100644
--- a/gn/core.gni
+++ b/gn/core.gni
@@ -34,8 +34,6 @@
   "$_src/core/SkThreadedBMPDevice.cpp",
   "$_src/core/SkThreadedBMPDevice.h",
   "$_src/core/SkBitmapFilter.h",
-  "$_src/core/SkBitmapProcShader.cpp",
-  "$_src/core/SkBitmapProcShader.h",
   "$_src/core/SkBitmapProcState.cpp",
   "$_src/core/SkBitmapProcState.h",
   "$_src/core/SkBitmapProcState_filter.h",
@@ -73,13 +71,10 @@
   "$_src/core/SkClipStackDevice.h",
   "$_src/core/SkColor.cpp",
   "$_src/core/SkColorFilter.cpp",
-  "$_src/core/SkColorFilterShader.cpp",
   "$_src/core/SkColorLookUpTable.cpp",
   "$_src/core/SkColorLookUpTable.h",
   "$_src/core/SkColorMatrixFilterRowMajor255.cpp",
   "$_src/core/SkColorMatrixFilterRowMajor255.h",
-  "$_src/core/SkColorShader.cpp",
-  "$_src/core/SkColorShader.h",
   "$_src/core/SkColorSpace.cpp",
   "$_src/core/SkColorSpace_A2B.cpp",
   "$_src/core/SkColorSpace_A2B.h",
@@ -93,7 +88,6 @@
   "$_src/core/SkColorSpaceXform_A2B.cpp",
   "$_src/core/SkColorSpaceXform_A2B.h",
   "$_src/core/SkColorTable.cpp",
-  "$_src/core/SkComposeShader.cpp",
   "$_src/core/SkConvertPixels.cpp",
   "$_src/core/SkConvertPixels.h",
   "$_src/core/SkConvolver.cpp",
@@ -129,7 +123,6 @@
   "$_src/core/SkEdgeBuilder.h",
   "$_src/core/SkEdgeClipper.cpp",
   "$_src/core/SkEdgeClipper.h",
-  "$_src/core/SkEmptyShader.h",
   "$_src/core/SkEndian.h",
   "$_src/core/SkExecutor.cpp",
   "$_src/core/SkAnalyticEdge.cpp",
@@ -172,8 +165,6 @@
   "$_src/core/SkImageInfo.cpp",
   "$_src/core/SkImageCacherator.h",
   "$_src/core/SkImageGenerator.cpp",
-  "$_src/core/SkLightingShader.h",
-  "$_src/core/SkLightingShader.cpp",
   "$_src/core/SkLights.cpp",
   "$_src/core/SkLinearBitmapPipeline.cpp",
   "$_src/core/SkLinearBitmapPipeline.h",
@@ -186,7 +177,6 @@
   "$_src/core/SkLiteRecorder.cpp",
   "$_src/core/SkLocalMatrixImageFilter.cpp",
   "$_src/core/SkLocalMatrixImageFilter.h",
-  "$_src/core/SkLocalMatrixShader.cpp",
   "$_src/core/SkMD5.cpp",
   "$_src/core/SkMD5.h",
   "$_src/core/SkMallocPixelRef.cpp",
@@ -253,8 +243,6 @@
   "$_src/core/SkPictureRecord.cpp",
   "$_src/core/SkPictureRecord.h",
   "$_src/core/SkPictureRecorder.cpp",
-  "$_src/core/SkPictureShader.cpp",
-  "$_src/core/SkPictureShader.h",
   "$_src/core/SkPixelRef.cpp",
   "$_src/core/SkPixmap.cpp",
   "$_src/core/SkPoint.cpp",
@@ -300,8 +288,6 @@
   "$_src/core/SkScan_Hairline.cpp",
   "$_src/core/SkScan_Path.cpp",
   "$_src/core/SkSemaphore.cpp",
-  "$_src/core/SkShader.cpp",
-  "$_src/core/SkShaderBase.h",
   "$_src/core/SkSharedMutex.cpp",
   "$_src/core/SkSharedMutex.h",
   "$_src/core/SkSinglyLinkedList.h",
@@ -376,8 +362,6 @@
   #        "$_src/image/SkImage_Gpu.cpp",
   "$_src/image/SkImage_Lazy.cpp",
   "$_src/image/SkImage_Raster.cpp",
-  "$_src/image/SkImageShader.cpp",
-  "$_src/image/SkImageShader.h",
   "$_src/image/SkSurface.cpp",
   "$_src/image/SkSurface_Base.h",
 
@@ -387,6 +371,26 @@
   "$_src/pipe/SkPipeCanvas.cpp",
   "$_src/pipe/SkPipeReader.cpp",
 
+  "$_src/shaders/SkBitmapProcShader.cpp",
+  "$_src/shaders/SkBitmapProcShader.h",
+  "$_src/shaders/SkColorFilterShader.cpp",
+  "$_src/shaders/SkColorFilterShader.h",
+  "$_src/shaders/SkColorShader.cpp",
+  "$_src/shaders/SkColorShader.h",
+  "$_src/shaders/SkComposeShader.cpp",
+  "$_src/shaders/SkComposeShader.h",
+  "$_src/shaders/SkEmptyShader.h",
+  "$_src/shaders/SkImageShader.cpp",
+  "$_src/shaders/SkImageShader.h",
+  "$_src/shaders/SkLightingShader.cpp",
+  "$_src/shaders/SkLightingShader.h",
+  "$_src/shaders/SkLocalMatrixShader.cpp",
+  "$_src/shaders/SkLocalMatrixShader.h",
+  "$_src/shaders/SkPictureShader.cpp",
+  "$_src/shaders/SkPictureShader.h",
+  "$_src/shaders/SkShader.cpp",
+  "$_src/shaders/SkShaderBase.h",
+
   "$_include/core/SkBBHFactory.h",
   "$_include/core/SkBitmap.h",
   "$_include/core/SkCanvas.h",