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 1fd3e705d5e4f2304056fdbbac68eb3bbd10b0d8..b5c818ca8fc48424f1572713b4e0c57c197d1081 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");

[fukino, 2014/04/15 07:29:00]

To force the MIME type to fall back to application/octet-stream,
test_binary.unknowextension is used here. This is a binary file whose content
was generated by random number generator.

   ASSERT_TRUE(RunPlatformAppTest(
       "platform_apps/launch_application_octet_stream")) << message_;
 }