Parsing filesystem url before giving it to media player

content/browser/fileapi/fileapi_message_filter.cc

Index: content/browser/fileapi/fileapi_message_filter.cc
diff --git a/content/browser/fileapi/fileapi_message_filter.cc b/content/browser/fileapi/fileapi_message_filter.cc
index 446cb8f1133c1e7c20ac7403e1d96bd916edb06c..14981da7de898f77174ffbb01208abcfd6c1c2f8 100644
--- a/content/browser/fileapi/fileapi_message_filter.cc
+++ b/content/browser/fileapi/fileapi_message_filter.cc
@@ -54,6 +54,56 @@ void RevokeFilePermission(int child_id, const base::FilePath& path) {
     child_id, path);
 }
 
+// Check whether a process has permission to access the file system URL.
+bool CheckFilePermissionsForProcess(
+    fileapi::FileSystemContext* context, int process_id,
+    const FileSystemURL& url, int permissions, base::PlatformFileError* error) {
+  DCHECK(error);
+  *error = base::PLATFORM_FILE_OK;
+
+  if (!url.is_valid()) {
+    *error = base::PLATFORM_FILE_ERROR_INVALID_URL;
+    return false;
+  }
+
+  FileSystemMountPointProvider* mount_point_provider =
+      context->GetMountPointProvider(url.type());
+  if (!mount_point_provider) {
+    *error = base::PLATFORM_FILE_ERROR_INVALID_URL;
+    return false;
+  }
+
+  base::FilePath file_path;
+  ChildProcessSecurityPolicyImpl* policy =
+      ChildProcessSecurityPolicyImpl::GetInstance();
+
+  switch (mount_point_provider->GetPermissionPolicy(url, permissions)) {
+    case fileapi::FILE_PERMISSION_ALWAYS_DENY:
+      *error = base::PLATFORM_FILE_ERROR_SECURITY;
+      return false;
+    case fileapi::FILE_PERMISSION_ALWAYS_ALLOW:
+      CHECK(mount_point_provider == context->sandbox_provider());
+      return true;
+    case fileapi::FILE_PERMISSION_USE_FILE_PERMISSION: {
+      const bool success = policy->HasPermissionsForFile(
+          process_id, url.path(), permissions);
+      if (!success)
+        *error = base::PLATFORM_FILE_ERROR_SECURITY;
+      return success;
+    }
+    case fileapi::FILE_PERMISSION_USE_FILESYSTEM_PERMISSION: {
+      const bool success = policy->HasPermissionsForFileSystem(
+          process_id, url.filesystem_id(), permissions);
+      if (!success)
+        *error = base::PLATFORM_FILE_ERROR_SECURITY;
+      return success;
+    }
+  }
+  NOTREACHED();
+  *error = base::PLATFORM_FILE_ERROR_SECURITY;
+  return false;
+}
+
 }  // namespace
 
 FileAPIMessageFilter::FileAPIMessageFilter(
@@ -295,6 +345,7 @@ void FileAPIMessageFilter::OnCreate(
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   base::PlatformFileError error;
   FileSystemURL url(context_->CrackURL(path));
+
   if (!HasPermissionsForFile(url, fileapi::kCreateFilePermissions, &error)) {
     Send(new FileSystemMsg_DidFail(request_id, error));
     return;
@@ -504,12 +555,15 @@ void FileAPIMessageFilter::OnDidUpdate(const GURL& path, int64 delta) {
   observers->Notify(&FileUpdateObserver::OnEndUpdate, MakeTuple(url));
 }
 
-void FileAPIMessageFilter::OnSyncGetPlatformPath(
-    const GURL& path, base::FilePath* platform_path) {
+void FileAPIMessageFilter::SyncGetPlatformPath(
+    fileapi::FileSystemContext* context,
+    int process_id,
+    const GURL& path,
+    base::FilePath* platform_path) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
   DCHECK(platform_path);
   *platform_path = base::FilePath();
-  FileSystemURL url(context_->CrackURL(path));
+  FileSystemURL url(context->CrackURL(path));
   if (!url.is_valid())
     return;
 
@@ -517,7 +571,8 @@ void FileAPIMessageFilter::OnSyncGetPlatformPath(
   // which means roughly same as the renderer is allowed to get the platform
   // path to the file).
   base::PlatformFileError error;
-  if (!HasPermissionsForFile(url, fileapi::kReadFilePermissions, &error))
+  if (!CheckFilePermissionsForProcess(context, process_id, url,
+                                      fileapi::kReadFilePermissions, &error))
     return;
 
   // This is called only by pepper plugin as of writing to get the
@@ -526,7 +581,7 @@ void FileAPIMessageFilter::OnSyncGetPlatformPath(
   // TODO(kinuko): this hack should go away once appropriate upload-stream
   // handling based on element types is supported.
   LocalFileSystemOperation* operation =
-      context_->CreateFileSystemOperation(
+      context->CreateFileSystemOperation(
           url, NULL)->AsLocalFileSystemOperation();
   DCHECK(operation);
   if (!operation)
@@ -538,12 +593,18 @@ void FileAPIMessageFilter::OnSyncGetPlatformPath(
   // for the file. (We first need to check if it can already be read not to
   // overwrite existing permissions)
   if (!ChildProcessSecurityPolicyImpl::GetInstance()->CanReadFile(
-          process_id_, *platform_path)) {
+          process_id, *platform_path)) {
     ChildProcessSecurityPolicyImpl::GetInstance()->GrantReadFile(
-        process_id_, *platform_path);
+        process_id, *platform_path);
   }
 }
 
+void FileAPIMessageFilter::OnSyncGetPlatformPath(
+    const GURL& path, base::FilePath* platform_path) {
+  FileAPIMessageFilter::SyncGetPlatformPath(context_, process_id_,
+                                            path, platform_path);
+}
+
 void FileAPIMessageFilter::OnCreateSnapshotFile(
     int request_id, const GURL& path) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
@@ -898,50 +959,8 @@ void FileAPIMessageFilter::RegisterFileAsBlob(
 
 bool FileAPIMessageFilter::HasPermissionsForFile(
     const FileSystemURL& url, int permissions, base::PlatformFileError* error) {
-  DCHECK(error);
-  *error = base::PLATFORM_FILE_OK;
-
-  if (!url.is_valid()) {
-    *error = base::PLATFORM_FILE_ERROR_INVALID_URL;
-    return false;
-  }
-
-  FileSystemMountPointProvider* mount_point_provider =
-      context_->GetMountPointProvider(url.type());
-  if (!mount_point_provider) {
-    *error = base::PLATFORM_FILE_ERROR_INVALID_URL;
-    return false;
-  }
-
-  base::FilePath file_path;
-  ChildProcessSecurityPolicyImpl* policy =
-      ChildProcessSecurityPolicyImpl::GetInstance();
-
-  switch (mount_point_provider->GetPermissionPolicy(url, permissions)) {
-    case fileapi::FILE_PERMISSION_ALWAYS_DENY:
-      *error = base::PLATFORM_FILE_ERROR_SECURITY;
-      return false;
-    case fileapi::FILE_PERMISSION_ALWAYS_ALLOW:
-      CHECK(mount_point_provider == context_->sandbox_provider());
-      return true;
-    case fileapi::FILE_PERMISSION_USE_FILE_PERMISSION: {
-      const bool success = policy->HasPermissionsForFile(
-          process_id_, url.path(), permissions);
-      if (!success)
-        *error = base::PLATFORM_FILE_ERROR_SECURITY;
-      return success;
-    }
-    case fileapi::FILE_PERMISSION_USE_FILESYSTEM_PERMISSION: {
-      const bool success = policy->HasPermissionsForFileSystem(
-          process_id_, url.filesystem_id(), permissions);
-      if (!success)
-        *error = base::PLATFORM_FILE_ERROR_SECURITY;
-      return success;
-    }
-  }
-  NOTREACHED();
-  *error = base::PLATFORM_FILE_ERROR_SECURITY;
-  return false;
+  return CheckFilePermissionsForProcess(context_, process_id_, url,
+                                        permissions, error);
 }
 
 FileSystemOperation* FileAPIMessageFilter::GetNewOperation(