Revert of Explicit control in tools of ANGLE frontend and backend

tools/gpu/GrContextFactory.cpp

Index: tools/gpu/GrContextFactory.cpp
diff --git a/tools/gpu/GrContextFactory.cpp b/tools/gpu/GrContextFactory.cpp
index 4f189942bd04aba810bd76a8d55a44e727a6f413..5e6494f77866c56ead1d5d1f60f8b4a287f0ca7e 100644
--- a/tools/gpu/GrContextFactory.cpp
+++ b/tools/gpu/GrContextFactory.cpp
@@ -117,24 +117,13 @@
                     glCtx = CreatePlatformGLTestContext(kGLES_GrGLStandard);
                     break;
 #if SK_ANGLE
-                case kANGLE_D3D9_ES2_ContextType:
-                    glCtx = CreateANGLETestContext(ANGLEBackend::kD3D9, ANGLEContextVersion::kES2);
-                    break;
-                case kANGLE_D3D11_ES2_ContextType:
-                    glCtx = CreateANGLETestContext(ANGLEBackend::kD3D11,
-                                                   ANGLEContextVersion::kES2);
-                    break;
-                case kANGLE_D3D11_ES3_ContextType:
-                    glCtx = CreateANGLETestContext(ANGLEBackend::kD3D11,
-                                                   ANGLEContextVersion::kES3);
-                    break;
-                case kANGLE_GL_ES2_ContextType:
-                    glCtx = CreateANGLETestContext(ANGLEBackend::kOpenGL,
-                                                   ANGLEContextVersion::kES2);
-                    break;
-                case kANGLE_GL_ES3_ContextType:
-                    glCtx = CreateANGLETestContext(ANGLEBackend::kOpenGL,
-                                                   ANGLEContextVersion::kES3);
+#   ifdef SK_BUILD_FOR_WIN
+                case kANGLE_ContextType:
+                    glCtx = CreateANGLEDirect3DGLTestContext();
+                    break;
+#   endif
+                case kANGLE_GL_ContextType:
+                    glCtx = CreateANGLEOpenGLGLTestContext();
                     break;
 #endif
                 case kCommandBuffer_ContextType: