SkMatrix44(const SkMatrix&) needs to initialize the type mask

Review URL: https://codereview.chromium.org/791723006
diff --git a/tests/Matrix44Test.cpp b/tests/Matrix44Test.cpp
index 13ead19..221c37d 100644
--- a/tests/Matrix44Test.cpp
+++ b/tests/Matrix44Test.cpp
@@ -104,6 +104,14 @@
     REPORTER_ASSERT(reporter, testMatrix == placeholderMatrix);
     REPORTER_ASSERT(reporter, testMatrix->isIdentity());
     REPORTER_ASSERT(reporter, *testMatrix == SkMatrix44::I());
+
+    // Verify that that constructing from an SkMatrix initializes everything.
+    SkMatrix44 scaleMatrix(SkMatrix44::kUninitialized_Constructor);
+    scaleMatrix.setScale(3, 4, 5);
+    REPORTER_ASSERT(reporter, scaleMatrix.isScale());
+    testMatrix = new(&scaleMatrix) SkMatrix44(SkMatrix::I());
+    REPORTER_ASSERT(reporter, testMatrix->isIdentity());
+    REPORTER_ASSERT(reporter, *testMatrix == SkMatrix44::I());
 }
 
 static void test_translate(skiatest::Reporter* reporter) {