Statically link libprotobuf_lite on Linux component builds

third_party/protobuf/README.chromium

 Name: Protocol Buffers
 Short Name: protobuf
 URL: https://github.com/google/protobuf
 License: BSD
 License File: LICENSE
 Version: 3.0.0-beta-3
 Revision: 3470b6895aa659b7559ed678e029a5338e535f14
 Security Critical: yes
 
 Steps used to create the current version:
 1. Pull the release from https://github.com/google/protobuf/releases
 2. Add build files (BUILD.gn, proto_library.gni, protobuf.gyp,
    protobuf_lite.gypi, protobuf_nacl.gyp).
 
    Be sure to update the list of source files, as additional .cc files and
    headers might have been added -- you need to find the transitive closure of
    include files required by targets.
 
    Other things to care about are defines required by protobuf on various
    platforms, warnings generated by compilers, and new dependencies introduced.
 3. Get open-source library six.py from https://pypi.python.org/pypi/six/ and add
    it to protobuf/third_party/six/six.py.
 4. Apply patches in patches/ (see the description below):
 
    $ for patch in patches/*; do patch -s -p1 < $patch; done
 
    For future releases, it will be worth looking into which patches still need
    to be applied.
-5. Generate descriptor_pb2.py using something like the following steps. Make
+5. Extract all globals to src/google/protobuf/globals.cc and prefix these
+   symbols with 'cr_'.  On Linux, the command
+
+   $ objdump -t -j.data -j.bss obj/third_party/protobuf/libprotobuf_lite.a
+
+   should produce the output
+
+   objdump: section '.bss' mentioned in a -j option, but not found in any input file
+   objdump: section '.data' mentioned in a -j option, but not found in any input file
+
+   This will require updating 0012-extract-globals.patch.
+6. Generate descriptor_pb2.py using something like the following steps. Make
    sure you've regenerated your buildfiles and will build protoc from the
    newly-modified sources above.
 
    $ cd $SRC_DIR
    $ ninja -C out/Debug protoc
    $ cd third_party/protobuf/src
    $ ../../../out/Debug/protoc --python_out=../python google/protobuf/descriptor.proto
 
-6. Add an __init__.py to protobuf/ that adds third_party/six/ to Python path.
-7. Update README.chromium.
+7. Add an __init__.py to protobuf/ that adds third_party/six/ to Python path.
+8. Update README.chromium.
 
 Description of the patches:
 
 - 0003-remove-static-initializers.patch
 
   This patch removes all static initializers from Chromium. The change in Status
   class is not completely compatible with upstream, but it's compatible enough
   to work in Chromium, which doesn't use this functionality yet. The work on
   upstreaming the removal of static initializers is in progress:
   https://github.com/google/protobuf/issues/1404
@@ skipping 19 matching lines @@
 
   These patches uninline some functions, resulting in a significant reduction
   (somewhere between 500 KB and 1 MB) of binary size.
 
 - 0011-libprotobuf_export.patch
 
   During merge with internal branch, the dll export attribute was accidentally
   removed in C++11 mode.
 
   Fixed in https://github.com/google/protobuf/pull/1549
+
+- 0012-extract-globals.patch
+
+  Fixes https://crbug.com/700120.  Moves everything that would have
+  gotten linked into .data or .bss sections into globals.cc so that
+  Chromium may build a shared library containing just protobuf
+  globals.  Also prefixes every symbol with 'cr_' to avoid conflicting
+  with symbols from the system protobuf.