Add assertions that the empty Platform::cryptographicallyRandomValues() overrides are not being use…

components/test_runner/test_common.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 "components/test_runner/test_common.h"
 
 #include "base/lazy_instance.h"
 #include "base/macros.h"
+#include "base/rand_util.h"
 #include "third_party/WebKit/public/platform/Platform.h"
 #include "third_party/WebKit/public/web/WebKit.h"
 
 namespace test_runner {
 
 namespace {
 
 const char layout_tests_pattern[] = "/LayoutTests/";
 const std::string::size_type layout_tests_pattern_size =
     sizeof(layout_tests_pattern) - 1;
 const char file_url_pattern[] = "file:/";
 const char file_test_prefix[] = "(file test):";
 const char data_url_pattern[] = "data:";
 const std::string::size_type data_url_pattern_size =
     sizeof(data_url_pattern) - 1;
 
 // This mock is used to initialize blink.
 class MockBlinkPlatform : NON_EXPORTED_BASE(public blink::Platform) {
  public:
   MockBlinkPlatform() {
     blink::initializeWithoutV8(this);
   }
   ~MockBlinkPlatform() override {}
   void cryptographicallyRandomValues(unsigned char* buffer,
-                                     size_t length) override {}
+                                     size_t length) override {
+    base::RandBytes(buffer, length);
+  }
+
  private:
   DISALLOW_COPY_AND_ASSIGN(MockBlinkPlatform);
 };
 
 base::LazyInstance<MockBlinkPlatform>::Leaky g_mock_blink_platform =
     LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
 
 std::string NormalizeLayoutTestURL(const std::string& url) {
   std::string result = url;
   size_t pos;
   if (!url.find(file_url_pattern) &&
       ((pos = url.find(layout_tests_pattern)) != std::string::npos)) {
     // adjust file URLs to match upstream results.
     result.replace(0, pos + layout_tests_pattern_size, file_test_prefix);
   } else if (!url.find(data_url_pattern)) {
     // URL-escape data URLs to match results upstream.
     std::string path = url.substr(data_url_pattern_size);
     result.replace(data_url_pattern_size, url.length(), path);
   }
   return result;
 }
 
 void EnsureBlinkInitialized() {
   g_mock_blink_platform.Get();
 }
 
 }  // namespace test_runner