Eliminate third_party/mojo/src from all targets' include paths

third_party/mojo/src/mojo/public/cpp/bindings/lib/buffer.h

Index: third_party/mojo/src/mojo/public/cpp/bindings/lib/buffer.h
diff --git a/third_party/mojo/src/mojo/public/cpp/bindings/lib/buffer.h b/third_party/mojo/src/mojo/public/cpp/bindings/lib/buffer.h
index c3b570e7767d5aee8a2e3593fa9a2d849d3e4179..99197f4ecd54ad4f1b5740c52a5fdee6213db854 100644
--- a/third_party/mojo/src/mojo/public/cpp/bindings/lib/buffer.h
+++ b/third_party/mojo/src/mojo/public/cpp/bindings/lib/buffer.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_BUFFER_H_
-#define MOJO_PUBLIC_CPP_BINDINGS_LIB_BUFFER_H_
+#ifndef THIRD_PARTY_MOJO_SRC_MOJO_PUBLIC_CPP_BINDINGS_LIB_BUFFER_H_
+#define THIRD_PARTY_MOJO_SRC_MOJO_PUBLIC_CPP_BINDINGS_LIB_BUFFER_H_
 
 #include <stddef.h>
 
@@ -21,4 +21,4 @@ class Buffer {
 }  // namespace internal
 }  // namespace mojo
 
-#endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_BUFFER_H_
+#endif  // THIRD_PARTY_MOJO_SRC_MOJO_PUBLIC_CPP_BINDINGS_LIB_BUFFER_H_