added a default constructor for GrBatchToXPOverrides

tests/GrPorterDuffTest.cpp

Index: tests/GrPorterDuffTest.cpp
diff --git a/tests/GrPorterDuffTest.cpp b/tests/GrPorterDuffTest.cpp
index 73d30aa0237887ab032124b4388a3f454be6d2f7..f738c97a945ac366611b3fbf430bbe9e2d6ddc1e 100644
--- a/tests/GrPorterDuffTest.cpp
+++ b/tests/GrPorterDuffTest.cpp
@@ -98,7 +98,6 @@ static void test_lcd_coverage(skiatest::Reporter* reporter, const GrCaps& caps)
     opt.fColorPOI.calcWithInitialValues(NULL, 0, 0, kNone_GrColorComponentFlags, false);
     // Setting 2nd to last value to false and last to true will force covPOI to LCD coverage.
     opt.fCoveragePOI.calcWithInitialValues(NULL, 0, 0, kNone_GrColorComponentFlags, false, true);
-    opt.fOverrides.fUsePLSDstRead = false;
 
     SkASSERT(!opt.fColorPOI.isOpaque());
     SkASSERT(!opt.fColorPOI.isSolidWhite());
@@ -291,7 +290,6 @@ static void test_color_unknown_with_coverage(skiatest::Reporter* reporter, const
                                                   false);
     optimizations.fCoveragePOI.calcWithInitialValues(nullptr, 0, 0, kNone_GrColorComponentFlags, 
                                                      true);
-    optimizations.fOverrides.fUsePLSDstRead = false;
 
     SkASSERT(!optimizations.fColorPOI.isOpaque());
     SkASSERT(!optimizations.fColorPOI.isSolidWhite());
@@ -486,7 +484,6 @@ static void test_color_unknown_no_coverage(skiatest::Reporter* reporter, const G
                                    kR_GrColorComponentFlag | kB_GrColorComponentFlag, false);
     optimizations.fCoveragePOI.calcWithInitialValues(nullptr, 0, GrColorPackA4(255), 
                                                      kRGBA_GrColorComponentFlags, true);
-    optimizations.fOverrides.fUsePLSDstRead = false;
 
     SkASSERT(!optimizations.fColorPOI.isOpaque());
     SkASSERT(!optimizations.fColorPOI.isSolidWhite());
@@ -691,7 +688,6 @@ static void test_color_opaque_with_coverage(skiatest::Reporter* reporter, const
                                                   kA_GrColorComponentFlag, false);
     optimizations.fCoveragePOI.calcWithInitialValues(nullptr, 0, 0, kNone_GrColorComponentFlags, 
                                                      true);
-    optimizations.fOverrides.fUsePLSDstRead = false;
 
     SkASSERT(optimizations.fColorPOI.isOpaque());
     SkASSERT(!optimizations.fColorPOI.isSolidWhite());
@@ -891,7 +887,6 @@ static void test_color_opaque_no_coverage(skiatest::Reporter* reporter, const Gr
                                    kG_GrColorComponentFlag | kA_GrColorComponentFlag, false);
     optimizations.fCoveragePOI.calcWithInitialValues(nullptr, 0, GrColorPackA4(255), 
                                                      kRGBA_GrColorComponentFlags, true);
-    optimizations.fOverrides.fUsePLSDstRead = false;
 
     SkASSERT(optimizations.fColorPOI.isOpaque());
     SkASSERT(!optimizations.fColorPOI.isSolidWhite());
@@ -1193,7 +1188,6 @@ DEF_GPUTEST(PorterDuffNoDualSourceBlending, reporter, /*factory*/) {
         GrPipelineOptimizations optimizations;
         optimizations.fColorPOI.calcWithInitialValues(nullptr, 0, testColors[c], testColorFlags[c], 
                                                       false);
-        optimizations.fOverrides.fUsePLSDstRead = false;
         for (int f = 0; f <= 1; f++) {
             if (!f) {
                 optimizations.fCoveragePOI.calcWithInitialValues(nullptr, 0, 0,