Revert 264167 "Sniff MIME type for files which have unknown exte..."

This revert is requested by fukino, who is the author of the patch.

This patch breaks a browser test on Windows. 

> Sniff MIME type for files which have unknown extensions.
> 
> What I want to do:
> Open text files which have unknown extensions(e.g. access.log.1) using packaged apps which can handle 'text/plain'(e.g. Text, Caret,...).
> 
> Current situation:
> By following reasons, text files with unknow extension can't be opened.
> 1. FileManager guess the MIME type as empty, so 'text/plain'-supporting apps are not shown as handlers.
> 2. PlatformAppLauncher guess the MIME type as 'application/octet-stream', and it launch apps with no data because those apps don't handle 'application/octet-stream'.
> 
> What I changed:
> Modified FileManager and PlatformAppLauncher to sniff MIME types if they are unknown based on extensions.
> 
> BUG=352250
> R=benwells@chromium.org, hashimoto@chromium.org, jorgelo@chromium.org
> 
> Review URL: https://codereview.chromium.org/224883008
> 
> Patch from Naoki Fukino <fukino@chromium.org>.

TBR=yoshiki@chromium.org

Review URL: https://codereview.chromium.org/240313002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@264192 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 2 insertions, 17 deletions

diff --git a/apps/launcher.cc b/apps/launcher.cc
index 8d31a01..ba7c829 100644
--- a/apps/launcher.cc
+++ b/apps/launcher.cc
@@ -29,8 +29,6 @@
 #include "extensions/common/extension.h"
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/manifest_handlers/kiosk_mode_info.h"
-#include "net/base/filename_util.h"
-#include "net/base/mime_sniffer.h"
 #include "net/base/mime_util.h"
 #include "net/base/net_util.h"
 #include "url/gurl.h"
@@ -183,21 +181,8 @@ class PlatformAppPathLauncher
     }
 
     std::string mime_type;
-    if (!net::GetMimeTypeFromFile(file_path_, &mime_type)) {
-      // If MIME type of the file can't be determined by its path,
-      // try to sniff it by its content.
-      std::vector<char> content(net::kMaxBytesToSniff);
-      int bytes_read = base::ReadFile(file_path_, &content[0], content.size());
-      if (bytes_read >= 0) {
-        net::SniffMimeType(&content[0],
-                           bytes_read,
-                           net::FilePathToFileURL(file_path_),
-                           std::string(),  // type_hint (passes no hint)
-                           &mime_type);
-      }
-      if (mime_type.empty())
-        mime_type = kFallbackMimeType;
-    }
+    if (!net::GetMimeTypeFromFile(file_path_, &mime_type))
+      mime_type = kFallbackMimeType;
 
     BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, base::Bind(
             &PlatformAppPathLauncher::LaunchWithMimeType, this, mime_type));