Fix context sharing between channels to be order-independent.

content/common/gpu/gpu_messages.h

Index: content/common/gpu/gpu_messages.h
diff --git a/content/common/gpu/gpu_messages.h b/content/common/gpu/gpu_messages.h
index 7d2f36edea42b520fef7d159bb063d7f26bc3549..d320da60b3af4a2d8169d655e29460974c5b7462 100644
--- a/content/common/gpu/gpu_messages.h
+++ b/content/common/gpu/gpu_messages.h
@@ -150,7 +150,7 @@ IPC_MESSAGE_CONTROL0(GpuMsg_Initialize)
 // This ID is a unique opaque identifier generated by the browser process.
 IPC_MESSAGE_CONTROL2(GpuMsg_EstablishChannel,
                      int /* client_id */,
-                     int /* share_client_id */)
+                     bool /* share_context */)
 
 // Tells the GPU process to close the channel identified by IPC channel
 // handle.  If no channel can be identified, do nothing.