Remove (unused) context option to remove shader swizzling

Bug: skia:
Change-Id: I0372f7782124c096370b42624b6c0a3aff8a90b0
Reviewed-on: https://skia-review.googlesource.com/40101
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/include/gpu/GrContextOptions.h b/include/gpu/GrContextOptions.h
index d01d072..65db523 100644
--- a/include/gpu/GrContextOptions.h
+++ b/include/gpu/GrContextOptions.h
@@ -46,10 +46,6 @@
     /** some gpus have problems with partial writes of the rendertarget */
     bool fUseDrawInsteadOfPartialRenderTargetWrite = false;
 
-    /** Force us to do all swizzling manually in the shader and don't rely on extensions to do
-        swizzling. */
-    bool fUseShaderSwizzling = false;
-
     /** Construct mipmaps manually, via repeated downsampling draw-calls. This is used when
         the driver's implementation (glGenerateMipmap) contains bugs. This requires mipmap
         level and LOD control (ie desktop or ES3). */
diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index 3434852..377ff48 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -598,10 +598,6 @@
 
     this->initShaderPrecisionTable(ctxInfo, gli, shaderCaps);
 
-    if (contextOptions.fUseShaderSwizzling) {
-        fTextureSwizzleSupport = false;
-    }
-
     if (kGL_GrGLStandard == standard) {
         if ((version >= GR_GL_VER(4, 0) || ctxInfo.hasExtension("GL_ARB_sample_shading")) &&
             ctxInfo.vendor() != kIntel_GrGLVendor) {