Make content verification see 0-byte files.

chrome/browser/extensions/extension_protocols_unittest.cc

 // Copyright 2014 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 <stddef.h>
 
 #include <memory>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 535 matching lines @@
   EXPECT_EQ(net::ERR_ACCESS_DENIED, DoRequest(*extension, kFooJs));
   test_job_delegate.WaitForDoneReading(extension->id());
 
   // Delete foo.js.
   ASSERT_TRUE(base::DieFileDie(foo_path, false));
   test_job_delegate.Reset();
   EXPECT_EQ(net::ERR_FILE_NOT_FOUND, DoRequest(*extension, kFooJs));
   test_job_delegate.WaitForDoneReading(extension->id());
 }
 
+// Tests that zero byte files correctly go through ContentVerifyJob.
+TEST_F(ExtensionProtocolsTest, VerificationSeenForZeroByteFile) {
+  const char kFooJsContents[] = "";  // Empty.

[Devlin, 2017/03/29 18:29:48]

This won't do something silly like write a file with a null terminator byte,
will it?  For paranoid sanity checking, can we file_util::GetFileSize() on it
and ASSERT it's 0?

[lazyboy, 2017/03/29 20:09:59]

Done.

+  JobDelegate test_job_delegate(kFooJsContents);
+  SetProtocolHandler(false);
+
+  const std::string kFooJs("foo.js");
+  // Create a temporary directory that a fake extension will live in and fill
+  // it with some test files.
+  base::ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+  base::FilePath foo_js(FILE_PATH_LITERAL("foo.js"));
+  ASSERT_TRUE(AddFileToDirectory(temp_dir.GetPath(), foo_js, kFooJsContents))
+      << "Failed to write " << temp_dir.GetPath().value() << "/"
+      << foo_js.value();
+
+  ExtensionBuilder builder;
+  builder
+      .SetManifest(DictionaryBuilder()
+                       .Set("name", "Foo")
+                       .Set("version", "1.0")
+                       .Set("manifest_version", 2)
+                       .Set("update_url",
+                            "https://clients2.google.com/service/update2/crx")
+                       .Build())
+      .SetID(crx_file::id_util::GenerateId("whatever"))
+      .SetPath(temp_dir.GetPath())
+      .SetLocation(Manifest::INTERNAL);
+  scoped_refptr<Extension> extension(builder.Build());
+
+  ASSERT_TRUE(extension.get());
+  content_verifier_->OnExtensionLoaded(testing_profile_.get(), extension.get());
+  // Wait for PostTask to ContentVerifierIOData::AddData() to finish.
+  content::RunAllPendingInMessageLoop();
+
+  // Request foo.js.
+  EXPECT_EQ(net::OK, DoRequest(*extension, kFooJs));
+  test_job_delegate.WaitForDoneReading(extension->id());
+}
+
 }  // namespace extensions