Add pdf_unittests target.

pdf/run_all_unittests.cc

Index: pdf/run_all_unittests.cc
diff --git a/ui/arc/test/run_all_unittests.cc b/pdf/run_all_unittests.cc
similarity index 77%
copy from ui/arc/test/run_all_unittests.cc
copy to pdf/run_all_unittests.cc
index 92e28e4bc2ef21acede81193f132cd22481f4a7d..138e5a2361f876dd773cc7ba93e2e9a18c383c62 100644
--- a/ui/arc/test/run_all_unittests.cc
+++ b/pdf/run_all_unittests.cc
@@ -2,15 +2,22 @@
 // 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"
-#include "mojo/edk/embedder/embedder.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);
-
-  mojo::edk::Init();
   return base::LaunchUnitTests(
       argc, argv,
       base::Bind(&base::TestSuite::Run, base::Unretained(&test_suite)));