Add IPC to allow gpu process to send message for console back to renderer

gpu/command_buffer/common/command_buffer.h

Index: gpu/command_buffer/common/command_buffer.h
diff --git a/gpu/command_buffer/common/command_buffer.h b/gpu/command_buffer/common/command_buffer.h
index e44df7feca907927ab3713f31e6e5773c9277164..ec4cc144e9e08197b978cd768b304d1c7be1608a 100644
--- a/gpu/command_buffer/common/command_buffer.h
+++ b/gpu/command_buffer/common/command_buffer.h
@@ -60,6 +60,13 @@ class CommandBuffer {
     uint32 generation;
   };
 
+  struct ConsoleMessage {
+    // An user supplied id.
+    int32 id;
+    // The message.
+    std::string message;
+  };
+
   CommandBuffer() {
   }