Revert of remove workaround for dx9 angle slow rgba pixel ops

src/gpu/gl/GrGLGpu.cpp

Index: src/gpu/gl/GrGLGpu.cpp
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index 6366b44e245f21550e72119e1763e47274885b59..20669b8e78bfcd7677cce97ff2a8575cb8516622 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -270,14 +270,21 @@
 ///////////////////////////////////////////////////////////////////////////////
 GrPixelConfig GrGLGpu::preferredReadPixelsConfig(GrPixelConfig readConfig,
                                                  GrPixelConfig surfaceConfig) const {
-    if (kMesa_GrGLDriver == this->glContext().driver() &&
-        GrBytesPerPixel(readConfig) == 4 && GrPixelConfigSwapRAndB(readConfig) == surfaceConfig) {
-        // Mesa 3D takes a slow path on when reading back BGRA from an RGBA surface and vice-versa.
-        // Perhaps this should be guarded by some compile-time or runtime check.
+    if (GR_GL_RGBA_8888_PIXEL_OPS_SLOW && kRGBA_8888_GrPixelConfig == readConfig) {
+        return kBGRA_8888_GrPixelConfig;
+    } else if (kMesa_GrGLDriver == this->glContext().driver() &&
+               GrBytesPerPixel(readConfig) == 4 &&
+               GrPixelConfigSwapRAndB(readConfig) == surfaceConfig) {
+        // Mesa 3D takes a slow path on when reading back  BGRA from an RGBA surface and vice-versa.
+        // Perhaps this should be guarded by some compiletime or runtime check.
         return surfaceConfig;
-    } else if (readConfig == kBGRA_8888_GrPixelConfig &&
-               !this->glCaps().readPixelsSupported(this->glInterface(), GR_GL_BGRA,
-                                                   GR_GL_UNSIGNED_BYTE, surfaceConfig)) {
+    } else if (readConfig == kBGRA_8888_GrPixelConfig
+            && !this->glCaps().readPixelsSupported(
+                this->glInterface(),
+                GR_GL_BGRA,
+                GR_GL_UNSIGNED_BYTE,
+                surfaceConfig
+            )) {
         return kRGBA_8888_GrPixelConfig;
     } else {
         return readConfig;
@@ -286,7 +293,11 @@
 
 GrPixelConfig GrGLGpu::preferredWritePixelsConfig(GrPixelConfig writeConfig,
                                                   GrPixelConfig surfaceConfig) const {
-    return writeConfig;
+    if (GR_GL_RGBA_8888_PIXEL_OPS_SLOW && kRGBA_8888_GrPixelConfig == writeConfig) {
+        return kBGRA_8888_GrPixelConfig;
+    } else {
+        return writeConfig;
+    }
 }
 
 bool GrGLGpu::canWriteTexturePixels(const GrTexture* texture, GrPixelConfig srcConfig) const {