Drop //ppapi/cpp dependency from pdf_unittests

pdf_unittests depends on both //ppapi/cpp and
//ppapi/cpp/private:internal_module, which should not be used together:
Both provide pp::Module::Get(), which would be an ODR violation (except
//ppapi/cpp is provided as a static library which doesn't end up getting
linked into pdf_unittests).

Since //ppapi/cpp isn't linked in anyway, this should be a no-op.

Note that only //ppapi/cpp requires a pp::CreateModule() definition, so
there's no need for a custom run_all_unittests.cc anymore.

Change-Id: I896ca1c50a4c57b87672882d75e040ea6713ba1b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1597469
Auto-Submit: K Moon <kmoon@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#656948}

pdf/BUILD.gn

@@ -152,16 +152,15 @@ if (enable_pdf) {
       "document_loader_impl_unittest.cc",
       "pdf_transform_unittest.cc",
       "range_set_unittest.cc",
-      "run_all_unittests.cc",
     ]
 
     deps = [
       ":pdf",
       ":pdf_test_utils",
       "//base",
+      "//base/test:run_all_unittests",
       "//base/test:test_support",
       "//ppapi/c",
-      "//ppapi/cpp",
       "//testing/gmock",
       "//testing/gtest",
       "//ui/gfx/range",

pdf/run_all_unittests.cc

@@ -1,25 +0,0 @@
-// Copyright 2016 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/test/launcher/unit_test_launcher.h"
-#include "base/test/test_suite.h"
-
-// ppapi_cpp won't link w/o this.
-namespace pp {
-
-class Module;
-
-Module* CreateModule() {
-  return nullptr;
-}
-
-}  // namespace pp
-
-int main(int argc, char** argv) {
-  base::TestSuite test_suite(argc, argv);
-  return base::LaunchUnitTests(
-      argc, argv,
-      base::BindOnce(&base::TestSuite::Run, base::Unretained(&test_suite)));
-}