Add an option to include a full bootloader in incremental OTA.

Bug: 23999213
Change-Id: I6c715eb01048e187622ba1e90c89a3306a294b8a
diff --git a/tools/releasetools/ota_from_target_files.py b/tools/releasetools/ota_from_target_files.py
index 9951b39..b148fc1 100755
--- a/tools/releasetools/ota_from_target_files.py
+++ b/tools/releasetools/ota_from_target_files.py
@@ -42,6 +42,11 @@
       radio image. This option is only meaningful when -i is specified,
       because a full radio is always included in a full OTA if applicable.
 
+ --full_bootloader
+      When generating an incremental OTA, always include a full copy of
+      bootloader image. This option is only meaningful when -i is specified,
+      because a full bootloader is always included in a full OTA if applicable.
+
   -v  (--verify)
       Remount and verify the checksums of the files written to the
       system and vendor (if used) partitions.  Incremental builds only.
@@ -122,6 +127,7 @@
 OPTIONS.oem_source = None
 OPTIONS.fallback_to_full = True
 OPTIONS.full_radio = False
+OPTIONS.full_bootloader = False
 
 def MostPopularKey(d, default):
   """Given a dict, return the key corresponding to the largest
@@ -1499,6 +1505,8 @@
       OPTIONS.incremental_source = a
     elif o == "--full_radio":
       OPTIONS.full_radio = True
+    elif o == "--full_bootloader":
+      OPTIONS.full_bootloader = True
     elif o in ("-w", "--wipe_user_data"):
       OPTIONS.wipe_user_data = True
     elif o in ("-n", "--no_prereq"):
@@ -1541,6 +1549,7 @@
                                  "package_key=",
                                  "incremental_from=",
                                  "full_radio",
+                                 "full_bootloader",
                                  "wipe_user_data",
                                  "no_prereq",
                                  "extra_script=",