Move ".crx"/".pem" constants and extension_filenames constants into extensions/common/constants.cc.

chrome/utility/extensions/unpacker_unittest.cc

Index: chrome/utility/extensions/unpacker_unittest.cc
diff --git a/chrome/utility/extensions/unpacker_unittest.cc b/chrome/utility/extensions/unpacker_unittest.cc
index 3a66b29838f2a492a650987043d5bf5b44559a3c..8ddd7376ffd9bf3f5dec11884852a7b01965e62a 100644
--- a/chrome/utility/extensions/unpacker_unittest.cc
+++ b/chrome/utility/extensions/unpacker_unittest.cc
@@ -10,14 +10,13 @@
 #include "base/values.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/extensions/extension.h"
-#include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/extensions/extension_manifest_constants.h"
 #include "chrome/utility/extensions/unpacker.h"
+#include "extensions/common/constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
 namespace errors = extension_manifest_errors;
-namespace filenames = extension_filenames;
 namespace keys = extension_manifest_keys;
 
 namespace extensions {
@@ -134,7 +133,7 @@ TEST_F(UnpackerTest, UnzipDirectoryError) {
   const char* kExpected = "Could not create directory for unzipping: ";
   SetupUnpacker("good_package.crx");
   base::FilePath path =
-      temp_dir_.path().AppendASCII(filenames::kTempExtensionName);
+      temp_dir_.path().AppendASCII(kTempExtensionName);
   ASSERT_TRUE(file_util::WriteFile(path, "foo", 3));
   EXPECT_FALSE(unpacker_->Run());
   EXPECT_TRUE(StartsWith(unpacker_->error_message(),