Use DiscardableMemoryManager on Android.

base/base.gypi

Index: base/base.gypi
diff --git a/base/base.gypi b/base/base.gypi
index 7f2d58fbce5075e0b81933a7913365f7a4df4345..8f36dc7ec16ee38fd50ea9900fad4da59d969e2b 100644
--- a/base/base.gypi
+++ b/base/base.gypi
@@ -314,8 +314,6 @@
           'memory/aligned_memory.h',
           'memory/discardable_memory.cc',
           'memory/discardable_memory.h',
-          'memory/discardable_memory_allocator_android.cc',
-          'memory/discardable_memory_allocator_android.h',
           'memory/discardable_memory_android.cc',
           'memory/discardable_memory_emulated.cc',
           'memory/discardable_memory_emulated.h',
@@ -797,6 +795,14 @@
               ['include', '^threading/platform_thread_linux\\.cc$'],
             ],
           }],
+          ['OS == "android" and _toolset == "target"', {

[reveman, 2014/03/20 19:33:43]

what is _toolset == "target" for?

[Philippe, 2014/03/21 10:17:44]

On platforms where cross-compilation is used, we distinguish the target (Android
here) and the host (Linux). In an Android build we build libbase not only for
the target but also for the host since we have some standalone binaries
(depending on base) that we use as part of the build itself and for testing.
Does that make sense?

+            'sources': [
+              'memory/discardable_memory_allocation_ashmem_factory.cc',
+              'memory/discardable_memory_allocation_ashmem_factory.h',
+              'memory/discardable_memory_ashmem.cc',
+              'memory/discardable_memory_ashmem.h',
+            ],
+          }],
           ['OS == "android" and >(nacl_untrusted_build)==0', {
             'sources!': [
               'base_paths_posix.cc',