VendorManifest and CompatibilityMatrix from and to XML.

Usage:

    #include <vintf/VendorManifest.h>
    #include <vintf/parse_xml.h>
    VendorManifest vm;
    // ...
    std::string xml = gVendorManifestConverter(vm);
    VendorManifest vm2;
    bool success = gVendorManifestConverter(&vm2, xml);
    if (!success)
        ALOGW("%s", gVendorManifestConverter.lastError());

See Vendor Interface Object and Compatibility Matrix Design
document and libvintf_test (test/main.cpp) for details.
(Up to commit 4468534)

Test: libvintf_test

Bug: 32648352

Change-Id: I7e8ee8d2b9e61bf036e77a390712480cbbd452b4
diff --git a/MatrixHal.cpp b/MatrixHal.cpp
new file mode 100644
index 0000000..aa6f7f3
--- /dev/null
+++ b/MatrixHal.cpp
@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MatrixHal.h"
+
+namespace android {
+namespace vintf {
+
+bool MatrixHal::operator==(const MatrixHal &other) const {
+    if (format != other.format)
+        return false;
+    if (name != other.name)
+        return false;
+    if (versionRanges != other.versionRanges)
+        return false;
+    // do not compare optional
+    return true;
+}
+
+} // namespace vintf
+} // namespace android