Improve Android support

This patch remove many Android-specific #ifdefs from the Breakpad
source code. This is achieved by providing "fixed-up" platform
headers (e.g. <signal.h> or <sys/user,h>), in the new directory
src/common/android/include/, which masks differences between
the NDK and GLibc headers.

The old "android_link.h" and "android_ucontext.h" are moved
and renamed.

This also requires putting this directory as the first
include path during Android-hosted builds, hence the
modification of Makefile.am and configure.ac
Review URL: https://breakpad.appspot.com/434002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1017 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/client/linux/minidump_writer/linux_dumper.h

@@ -42,9 +42,7 @@
 #include <linux/limits.h>
 #include <stdint.h>
 #include <sys/types.h>
-#if !defined(__ANDROID__)
 #include <sys/user.h>
-#endif
 
 #include "common/memory.h"
 #include "google_breakpad/common/minidump_format.h"
@@ -57,23 +55,7 @@ typedef typeof(((struct user*) 0)->u_debugreg[0]) debugreg_t;
 
 // Typedef for our parsing of the auxv variables in /proc/pid/auxv.
 #if defined(__i386) || defined(__ARM_EABI__)
-#if !defined(__ANDROID__)
 typedef Elf32_auxv_t elf_aux_entry;
-#else
-// Android is missing this structure definition
-typedef struct
-{
-  uint32_t a_type;              /* Entry type */
-  union
-    {
-      uint32_t a_val;           /* Integer value */
-    } a_un;
-} elf_aux_entry;
-
-#if !defined(AT_SYSINFO_EHDR)
-#define AT_SYSINFO_EHDR 33
-#endif
-#endif  // __ANDROID__
 #elif defined(__x86_64)
 typedef Elf64_auxv_t elf_aux_entry;
 #endif
@@ -104,12 +86,8 @@ struct ThreadInfo {
 
 #elif defined(__ARM_EABI__)
   // Mimicking how strace does this(see syscall.c, search for GETREGS)
-#if defined(__ANDROID__)
-  struct pt_regs regs;
-#else
   struct user_regs regs;
   struct user_fpregs fpregs;
-#endif  // __ANDROID__
 #endif
 };