Video Player: Fix the private API error in Debug build

BUG=400892
TEST=manually tested

Review URL: https://codereview.chromium.org/450913002

Cr-Commit-Position: refs/heads/master@{#288321}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288321 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/chromeos/extensions/file_manager/private_api_drive.cc

@@ -918,7 +918,11 @@ bool FileBrowserPrivateGetDownloadUrlFunction::RunAsync() {
 
   const base::FilePath path = file_manager::util::GetLocalPathFromURL(
       render_view_host(), GetProfile(), GURL(params->url));
-  DCHECK(drive::util::IsUnderDriveMountPoint(path));
+  if (!drive::util::IsUnderDriveMountPoint(path)) {
+    SetError("The given file is not in Drive.");
+    SetResult(new base::StringValue(""));  // Intentionally returns a blank.
+    return false;
+  }
   base::FilePath file_path = drive::util::ExtractDrivePath(path);
 
   file_system->GetResourceEntry(

ui/file_manager/video_player/js/cast/media_manager.js

@@ -51,6 +51,10 @@ MediaManager.prototype.getToken = function(refresh) {
     // TODO(yoshiki): Creates the method to get a token and use it.
     chrome.fileBrowserPrivate.getDownloadUrl(this.entry_.toURL(), fulfill);
   }.bind(this)).then(function(url) {
+    if (chrome.runtime.lastError) {
+      return Promise.reject(
+          'Token fetch failed: ' + chrome.runtime.lastError.message);
+    }
     if (!url)
       return Promise.reject('Token fetch failed.');
     var token = url.substring(url.indexOf('access_token=') + 13);
@@ -76,6 +80,10 @@ MediaManager.prototype.getUrl = function() {
     // TODO(yoshiki): Creates the method to get a url and use it.
     chrome.fileBrowserPrivate.getDownloadUrl(this.entry_.toURL(), fulfill);
   }.bind(this)).then(function(url) {
+    if (chrome.runtime.lastError) {
+      return Promise.reject(
+          'URL fetch failed: ' + chrome.runtime.lastError.message);
+    }
     if (!url)
       return Promise.reject('URL fetch failed.');
     var access_token_index = url.indexOf('access_token=');