Extensions: Fix/add base::WriteFile assertions in two test files.

Bug: None
Change-Id: I89c72bc8905a6a7dd8e339ba328e92e67f949b3e
Reviewed-on: https://chromium-review.googlesource.com/894504Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Istiaque Ahmed <lazyboy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533327}

extensions/browser/content_verify_job_unittest.cc

@@ -181,7 +181,9 @@ TEST_F(ContentVerifyJobUnittest, DeletedAndMissingFiles) {
 
     base::FilePath full_path =
         unzipped_path.Append(base::FilePath(unexpected_resource_path));
-    base::WriteFile(full_path, "42", sizeof("42"));
+    const std::string kContent("42");
+    EXPECT_EQ(static_cast<int>(kContent.size()),
+              base::WriteFile(full_path, kContent.data(), kContent.size()));
 
     std::string contents;
     base::ReadFileToString(full_path, &contents);

extensions/browser/json_file_sanitizer_unittest.cc

@@ -31,12 +31,14 @@ class JsonFileSanitizerTest : public testing::Test {
 
   void CreateValidJsonFile(const base::FilePath& path) {
     std::string kJson = "{\"hello\":\"bonjour\"}";
-    ASSERT_TRUE(base::WriteFile(path, kJson.data(), kJson.size()));
+    ASSERT_EQ(static_cast<int>(kJson.size()),
+              base::WriteFile(path, kJson.data(), kJson.size()));
   }
 
   void CreateInvalidJsonFile(const base::FilePath& path) {
     std::string kJson = "sjkdsk;'<?js";
-    ASSERT_TRUE(base::WriteFile(path, kJson.data(), kJson.size()));
+    ASSERT_EQ(static_cast<int>(kJson.size()),
+              base::WriteFile(path, kJson.data(), kJson.size()));
   }
 
   const base::FilePath& GetJsonFilePath() const { return temp_dir_.GetPath(); }