Fix network service crash when --log-net-log flag isn't valid

Bug: 931502
Change-Id: I081a32b007d9dad40007b04821548df9ae5c3619
Reviewed-on: https://chromium-review.googlesource.com/c/1471022
Commit-Queue: Robbie McElrath <rmcelrath@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#631997}

content/browser/network_service_browsertest.cc

@@ -29,6 +29,7 @@
 #include "net/http/http_response_headers.h"
 #include "net/traffic_annotation/network_traffic_annotation_test_helper.h"
 #include "services/network/public/cpp/features.h"
+#include "services/network/public/cpp/network_switches.h"
 #include "services/network/public/cpp/resource_request.h"
 #include "services/network/public/cpp/simple_url_loader.h"
 #include "services/network/public/mojom/network_service_test.mojom.h"
@@ -364,6 +365,39 @@ IN_PROC_BROWSER_TEST_F(NetworkServiceInProcessBrowserTest, Basic) {
             LoadBasicRequest(partition->GetNetworkContext(), test_url));
 }
 
+class NetworkServiceInvalidLogBrowserTest : public ContentBrowserTest {
+ public:
+  NetworkServiceInvalidLogBrowserTest() {
+    scoped_feature_list_.InitAndEnableFeature(
+        network::features::kNetworkService);
+  }
+
+  void SetUpCommandLine(base::CommandLine* command_line) override {
+    command_line->AppendSwitchASCII(network::switches::kLogNetLog, "/abc/def");
+  }
+
+  void SetUpOnMainThread() override {
+    host_resolver()->AddRule("*", "127.0.0.1");
+    EXPECT_TRUE(embedded_test_server()->Start());
+  }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(NetworkServiceInvalidLogBrowserTest);
+};
+
+// Verifies that an invalid --log-net-log flag won't crash the browser.
+IN_PROC_BROWSER_TEST_F(NetworkServiceInvalidLogBrowserTest, Basic) {
+  GURL test_url = embedded_test_server()->GetURL("foo.com", "/echo");
+  StoragePartitionImpl* partition = static_cast<StoragePartitionImpl*>(
+      BrowserContext::GetDefaultStoragePartition(
+          shell()->web_contents()->GetBrowserContext()));
+  NavigateToURL(shell(), test_url);
+  ASSERT_EQ(net::OK,
+            LoadBasicRequest(partition->GetNetworkContext(), test_url));
+}
+
 }  // namespace
 
 }  // namespace content

content/browser/network_service_instance.cc

@@ -129,14 +129,15 @@ CONTENT_EXPORT network::mojom::NetworkService* GetNetworkServiceFromConnector(
 
           base::File file(log_path, base::File::FLAG_CREATE_ALWAYS |
                                         base::File::FLAG_WRITE);
-          LOG_IF(ERROR, !file.IsValid())
-              << "Failed opening: " << log_path.value();
-
-          // TODO(mmenke): Get capture mode from the command line.
-          (*g_network_service_ptr)
-              ->StartNetLog(std::move(file),
-                            network::mojom::NetLogCaptureMode::DEFAULT,
-                            std::move(client_constants));
+          if (!file.IsValid()) {
+            LOG(ERROR) << "Failed opening: " << log_path.value();
+          } else {
+            // TODO(mmenke): Get capture mode from the command line.
+            (*g_network_service_ptr)
+                ->StartNetLog(std::move(file),
+                              network::mojom::NetLogCaptureMode::DEFAULT,
+                              std::move(client_constants));
+          }
         }
       }