Initialize blink::Platform in pdf_unittests

Calls blink::Platform::InitializeBlink() from pdf_unittests's main().
This allows the use of primitive Blink types like blink::WebString in
tests. (Specifically, this depends on initializing WTF.)

Bug: 1099022
Change-Id: I9ca8b88645870c0d834225458f6d2e34958d3948
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2390864Reviewed-by: Daniel Hosseinian <dhoss@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: K. Moon <kmoon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803923}

pdf/BUILD.gn

@@ -310,6 +310,7 @@ if (enable_pdf) {
       "pdfium/pdfium_test_base.h",
       "ppapi_migration/geometry_conversions_unittest.cc",
       "range_set_unittest.cc",
+      "test/run_all_unittests.cc",
     ]
 
     configs += [
@@ -328,7 +329,6 @@ if (enable_pdf) {
       ":pdf_test_utils",
       ":ppapi_migration",
       "//base",
-      "//base/test:run_all_unittests",
       "//base/test:test_support",
       "//gin",
       "//ppapi/c",
@@ -337,6 +337,7 @@ if (enable_pdf) {
       "//skia",
       "//testing/gmock",
       "//testing/gtest",
+      "//third_party/blink/public:blink",
       "//third_party/pdfium",
       "//ui/gfx:test_support",
       "//ui/gfx/geometry",

pdf/test/run_all_unittests.cc

+// Copyright 2020 The Chromium 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 "base/bind.h"
+#include "base/callback.h"
+#include "base/test/launcher/unit_test_launcher.h"
+#include "base/test/test_suite.h"
+#include "third_party/blink/public/platform/platform.h"
+
+namespace {
+
+class PdfTestSuite final : public base::TestSuite {
+ public:
+  using TestSuite::TestSuite;
+  PdfTestSuite(const PdfTestSuite&) = delete;
+  PdfTestSuite& operator=(const PdfTestSuite&) = delete;
+
+ protected:
+  void Initialize() override {
+    TestSuite::Initialize();
+    blink::Platform::InitializeBlink();
+  }
+};
+
+}  // namespace
+
+int main(int argc, char** argv) {
+  PdfTestSuite test_suite(argc, argv);
+  return base::LaunchUnitTests(
+      argc, argv,
+      base::BindOnce(&PdfTestSuite::Run, base::Unretained(&test_suite)));
+}