Remove dependency on --gc-sections for most Android debug targets.

chrome/chrome_android.gypi

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 {
   'variables': {
     'chromium_code': 1,
     'package_name': 'chrome_shell_apk',
   },
   'includes': [
     'chrome_android_paks.gypi', # Included for the list of pak resources.
@@ skipping 26 matching lines @@
             [ 'OS=="android"', {
               'dependencies': [ '../tools/cygprofile/cygprofile.gyp:cygprofile', ],
             }],
           ],
         }],
         # TODO(dmikurube): Kill android_use_tcmalloc. http://crbug.com/345554
         [ '(use_allocator!="none" and use_allocator!="see_use_tcmalloc") or (use_allocator=="see_use_tcmalloc" and android_use_tcmalloc==1)', {
           'dependencies': [
             '../base/allocator/allocator.gyp:allocator', ],
         }],
+        ['OS=="android"', {
+          'ldflags': [
+            # Some android targets depend on --gc-sections to link.
+            # Force --gc-sections also for Debug builds (see crbug.com/159847).
+            '-Wl,--gc-sections',

[Nico, 2014/04/11 20:36:59]

The idea is to remove this too eventually, right (if I get the CL description
right)? Say "TODO: remove" in front of the bug link

[Primiano Tucci (use gerrit), 2014/04/12 10:26:00]

Right. However the chrome layer on Android is damn more messy: there are several
hundreds linking errors (when disabling gc-sections) coming mostly from
extensions support code. That might take much more than a couple of days of
headaches, as it was in this case.
My priority at the moment is cleaning up at least the content layer at the other
targets, remove the global --gc-sections blanket and avoid future regressions,
at least on all-but-two targets.

FTR all this started as a consequence of the arm64 bringup. The linker in the
arm64 toolchain  still doesn't support --gc-sections.
In general the idea that we need the linker GC to build makes me extremely
grumpy. I find linker GC a great way to reduce binary size, but using it as a
precondition for building....brrrr)
 

+          ],
+        }],
       ],
     },
     {
       'target_name': 'chrome_shell_apk',
       'type': 'none',
       'dependencies': [
         'chrome_java',
         'chrome_shell_paks',
         'libchromeshell',
         '../media/media.gyp:media_java',
@@ skipping 68 matching lines @@
         {
           'destination': '<(chrome_android_pak_output_folder)',
           'files': [
             '<@(chrome_android_pak_input_resources)',
           ],
         }
       ],
     },
   ],
 }