Sniff MIME type for files which have unknown extensions.

chrome/browser/apps/app_browsertest.cc

Index: chrome/browser/apps/app_browsertest.cc
diff --git a/chrome/browser/apps/app_browsertest.cc b/chrome/browser/apps/app_browsertest.cc
index c87b2bf6032dc50d500e66ecde0de7c1de5b6c61..34591b8416ad28c1c315595e5fae3caa17bdc7b5 100644
--- a/chrome/browser/apps/app_browsertest.cc
+++ b/chrome/browser/apps/app_browsertest.cc
@@ -652,10 +652,18 @@ IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, LaunchWithNoIntent) {
       << message_;
 }
 
+// Tests that launch data is sent through when the file has unknown extension
+// but the MIME type can be sniffed and the sniffed type matches.
+IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, LaunchWithSniffableType) {
+  SetCommandLineArg("platform_apps/launch_files/test.unknownextension");
+  ASSERT_TRUE(RunPlatformAppTest(
+      "platform_apps/launch_file_by_extension_and_type")) << message_;
+}
+
 // Tests that launch data is sent through with the MIME type set to
 // application/octet-stream if the file MIME type cannot be read.
 IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, LaunchNoType) {
-  SetCommandLineArg("platform_apps/launch_files/test.unknownextension");
+  SetCommandLineArg("platform_apps/launch_files/test_binary.unknownextension");
   ASSERT_TRUE(RunPlatformAppTest(
       "platform_apps/launch_application_octet_stream")) << message_;
 }