Bug 977372 - Close IPC'd filedescriptor from device descriptor when finished with it. r=mikeh

dom/camera/DOMCameraControl.cpp

@@ -11,6 +11,7 @@
 #include "DeviceStorage.h"
 #include "DeviceStorageFileDescriptor.h"
 #include "mozilla/dom/TabChild.h"
+#include "mozilla/FileUtils.h"
 #include "mozilla/MediaManager.h"
 #include "mozilla/Services.h"
 #include "mozilla/unused.h"
@@ -728,7 +729,11 @@ nsDOMCameraControl::OnCreatedFileDescriptor(bool aSucceeded)
       return;
     }
   }
-
+  // An error occured. We need to manually close the file descriptor since
+  // the FileDescriptor destructor doesn't close file handles which originate
+  // from other processes.
+  int fd = mDSFileDescriptor->mFileDescriptor.PlatformHandle();
+  ScopedClose autoClose(fd);
   OnError(CameraControlListener::kInStartRecording, NS_LITERAL_STRING("FAILURE"));
 }
 

dom/camera/GonkCameraControl.cpp

@@ -856,7 +856,11 @@ nsGonkCameraControl::StartRecordingImpl(DeviceStorageFileDescriptor* aFileDescri
   }
 
   nsresult rv;
+  // SetupRecording creates a dup of the file descriptor, and since it
+  // was created in the parent, the FileDescriptor destructor won't close
+  // it, so we go ahead and close it once we leave this function.
   int fd = aFileDescriptor->mFileDescriptor.PlatformHandle();
+  ScopedClose autoClose(fd);
   if (aOptions) {
     rv = SetupRecording(fd, aOptions->rotation, aOptions->maxFileSizeBytes,
                         aOptions->maxVideoLengthMs);