Use a pdfium-specific unittest main rather than gtest's

We must initialize our partition allocator before calling into
any test cases.

We can then remove the FPDF_Test class, which did the same thing.

Change-Id: I614480fa474b2032052857a02e94781f15a27a4e
Reviewed-on: https://pdfium-review.googlesource.com/4473
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/testing/unit_test_main.cpp b/testing/unit_test_main.cpp
new file mode 100644
index 0000000..d8076ab
--- /dev/null
+++ b/testing/unit_test_main.cpp
@@ -0,0 +1,16 @@
+// Copyright 2017 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/fxcrt/fx_memory.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+// Can't use gtest-provided main since we need to initialize partition
+// alloc before invoking any test.
+int main(int argc, char** argv) {
+  FXMEM_InitalizePartitionAlloc();
+  testing::InitGoogleTest(&argc, argv);
+  testing::InitGoogleMock(&argc, argv);
+  return RUN_ALL_TESTS();
+}