Move bzip.h to payload_generator.

The in-memory bzip compression and decompression functions are only
used during payload generation and testing. This patch moves those
functions to the payload_generator/ directory and keeps the streamed
version (bzip_extent_writter.h) in the update_engine daemon.

Bug: None
Test: FEATURES=test emerge-link update_engine; `mm` on Brillo.

Change-Id: I78227fdac15df6461b23debb41c72207b22fb5db
diff --git a/update_engine.gyp b/update_engine.gyp
index 5d229ec..52b8f0f 100644
--- a/update_engine.gyp
+++ b/update_engine.gyp
@@ -160,7 +160,6 @@
         'action_processor.cc',
         'boot_control_chromeos.cc',
         'boot_control_stub.cc',
-        'bzip.cc',
         'bzip_extent_writer.cc',
         'certificate_checker.cc',
         'chrome_browser_proxy_resolver.cc',
@@ -292,6 +291,7 @@
         'payload_generator/annotated_operation.cc',
         'payload_generator/blob_file_writer.cc',
         'payload_generator/block_mapping.cc',
+        'payload_generator/bzip.cc',
         'payload_generator/cycle_breaker.cc',
         'payload_generator/delta_diff_generator.cc',
         'payload_generator/delta_diff_utils.cc',
@@ -429,6 +429,7 @@
             'payload_generator/payload_file_unittest.cc',
             'payload_generator/tarjan_unittest.cc',
             'payload_generator/topological_sort_unittest.cc',
+            'payload_generator/zip_unittest.cc',
             'payload_state_unittest.cc',
             'postinstall_runner_action_unittest.cc',
             'prefs_unittest.cc',
@@ -453,7 +454,6 @@
             'update_manager/variable_unittest.cc',
             'utils_unittest.cc',
             'xz_extent_writer_unittest.cc',
-            'zip_unittest.cc',
             # Main entry point for runnning tests.
             'testrunner.cc',
           ],