Update breakpad to support Android NDK r10c

Prior to NDK r10c, Breakpad was privately backporting these system
headers. This change is now unforking and removing those headers and
using the ones from the NDK.
Rationale:
 - They are finally available in the NDK, so there is no need to keep
   maintaining a fork (which was necessary up until recently to support
   arm64).
 - These forked headers, as they are today, are not compatible with the
   latest NDK (i.e. this change is required to roll NDK r10c).
   The forked ucontext.h, being removed by this CL, depends on some
   transitional features which are not compatible with the NDK release
   being targeted here.

After this change, the NDK r10c is now required to build Breakpad on
Android. Note that NDK releases are backwards compatible and contain all
the previous API levels, so this change is NOT effectively enforcing to
build against any particular Android SDK.

Submitting this on behalf of fdegans@chromium.org

BUG=chromium:358831
R=mark@chromium.org, primiano@chromium.org, rmcilroy@chromium.org

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1396 4c0a9323-5329-0410-9bdc-e9ce6186880e
diff --git a/README.ANDROID b/README.ANDROID
index 386fba1..f7eacdd 100644
--- a/README.ANDROID
+++ b/README.ANDROID
@@ -6,6 +6,7 @@
 it generates.
 
 This release supports ARM, x86 and MIPS based Android systems.
+This release requires NDK release r10c or higher.
 
 I. Building the client library:
 ===============================
@@ -36,8 +37,8 @@
       It has been tested succesfully with both STLport and GNU libstdc++
 
 
-II.1. Building with a standalone Android toolchain:
----------------------------------------------------
+I.2. Building with a standalone Android toolchain:
+--------------------------------------------------
 
 All you need to do is configure your build with the right 'host'
 value, and disable the processor and tools, as in: