Revert of PPAPI regression test for NaCl x86-32 IRT stack alignment sensitivity (patchset #3 id:40001 of https://codereview.chromium.org/1380853002/ )

Reason for revert:
The new test fails on Linux.

https://build.chromium.org/p/chromium.linux/builders/Linux%20Tests%20%28dbg%29%281%29%2832%29/builds/20294/steps/browser_tests/logs/PPAPINaClPNaClNonSfiTest.NaClIRTStackAlignment

Original issue's description:
> PPAPI regression test for NaCl x86-32 IRT stack alignment sensitivity
>
> The bug with IRT stack alignment sensitivity can manifest in two ways.
> The issue of the stack being aligned properly at callbacks from the
> IRT is tested on the NaCl side (irt_stack_alignment test).  The other
> issue is alignment-sensitive SSE instructions being used to copy
> 16-byte arguments from the stack, assuming they will be properly
> aligned on the stack.  That situation only comes up with the PPAPI
> interfaces that use a 16-byte argument type such as PP_Var.  So test
> that case here.
>
> BUG= https://code.google.com/p/nativeclient/issues/detail?id=3935
> TEST= browser_tests --gtest_filter=PPAPINaClNewlibTest.NaClIRTStackAlignment on x86-32
> R=bbudge@chromium.org, dschuff@chromium.org
>
> Committed: https://crrev.com/7c6a2aec822f5a9a25f9750a4ac934fc9e6d3910
> Cr-Commit-Position: refs/heads/master@{#351644}

TBR=bbudge@chromium.org,dschuff@chromium.org,mcgrathr@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG= https://code.google.com/p/nativeclient/issues/detail?id=3935

Review URL: https://codereview.chromium.org/1379023003

Cr-Commit-Position: refs/heads/master@{#351746}

4 files changed, 0 insertions, 121 deletions

diff --git a/chrome/test/ppapi/ppapi_browsertest.cc b/chrome/test/ppapi/ppapi_browsertest.cc
index d6de8fc..3cc2716 100644
--- a/chrome/test/ppapi/ppapi_browsertest.cc
+++ b/chrome/test/ppapi/ppapi_browsertest.cc
@@ -540,10 +540,6 @@ TEST_PPAPI_NACL(Var)
 
 TEST_PPAPI_NACL(VarResource)
 
-#if defined(__i386__)
-TEST_PPAPI_NACL(NaClIRTStackAlignment)
-#endif
-
 // PostMessage tests.
 #define RUN_POSTMESSAGE_SUBTESTS \
   RunTestViaHTTP( \
diff --git a/ppapi/ppapi_sources.gypi b/ppapi/ppapi_sources.gypi
index ea7ccbb..55e1ff2 100644
--- a/ppapi/ppapi_sources.gypi
+++ b/ppapi/ppapi_sources.gypi
@@ -513,8 +513,6 @@
     #
     'test_nacl_source_files': [
       # Test cases (PLEASE KEEP THIS SECTION IN ALPHABETICAL ORDER)
-      'tests/test_nacl_irt_stack_alignment.cc',
-      'tests/test_nacl_irt_stack_alignment.h',
       'tests/test_tcp_server_socket_private_disallowed.cc',
       'tests/test_tcp_socket_private_disallowed.cc',
       'tests/test_udp_socket_private_disallowed.cc',
diff --git a/ppapi/tests/test_nacl_irt_stack_alignment.cc b/ppapi/tests/test_nacl_irt_stack_alignment.cc
deleted file mode 100644
index 3766d4d..0000000
--- a/ppapi/tests/test_nacl_irt_stack_alignment.cc
+++ /dev/null
@@ -1,85 +0,0 @@
-// Copyright (c) 2015 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.
-
-#include "ppapi/tests/test_nacl_irt_stack_alignment.h"
-
-#include "ppapi/c/pp_var.h"
-#include "ppapi/c/ppb_var.h"
-#include "ppapi/cpp/instance.h"
-#include "ppapi/cpp/module.h"
-#include "ppapi/cpp/var.h"
-#include "ppapi/tests/testing_instance.h"
-
-// This whole test is really only meant for x86-32 NaCl.
-//
-// This is a regression test for the IRT code being sensitive to stack
-// alignment.  The de jure ABI is that the stack should be aligned to
-// 16 bytes at call sites.  However, the de facto ABI is that the IRT
-// worked in the past when called with misaligned stack.  NaCl code is
-// now compiled to expect the proper 16-byte alignment, but the IRT
-// code must remain compatible with old binaries that failed to do so.
-
-#if defined(__i386__)
-
-REGISTER_TEST_CASE(NaClIRTStackAlignment);
-
-bool TestNaClIRTStackAlignment::Init() {
-  var_interface_ = static_cast<const PPB_Var*>(
-      pp::Module::Get()->GetBrowserInterface(PPB_VAR_INTERFACE));
-  return var_interface_ && CheckTestingInterface();
-}
-
-void TestNaClIRTStackAlignment::RunTests(const std::string& filter) {
-  RUN_TEST(MisalignedCallVarAddRef, filter);
-}
-
-// This calls the given function with the stack explicitly misaligned.
-// If the function (in the IRT) was compiled wrongly, it will crash.
-void MisalignedCall(void (*func)(PP_Var), const PP_Var* arg)
-    asm("MisalignedCall") __attribute__((regparm(2)));
-
-// regparm(2) means: First argument in %eax, second argument in %edx.
-// Writing this with an inline asm would require explaining all the
-// call-clobbers register behavior in the asm clobber list, which is a
-// lot with all the SSE and FPU state.  It's far simpler just to make
-// it a function call the compiler knows is a function call, and then
-// write the function itself in pure assembly.
-asm("MisalignedCall:\n"
-    // Use an SSE register to copy the 16 bytes of memory.
-    // Note this instruction does not care about alignment.
-    // The pointer is not necessarily aligned to 16 bytes.
-    "movups (%edx), %xmm0\n"
-    // Set up a frame so we can recover the stack pointer after alignment.
-    "push %ebp\n"
-    "mov %esp, %ebp\n"
-    // Align the stack properly to 16 bytes.
-    "andl $-16, %esp\n"
-    // Now make space for the 16 bytes of argument data,
-    // plus another 4 bytes so the stack pointer is misaligned.
-    "subl $20, %esp\n"
-    // Copy the argument onto the (misaligned) top of stack.
-    "movups %xmm0, (%esp)\n"
-    // Now call into the IRT, and hilarity ensues.
-    "naclcall %eax\n"
-    // Standard epilogue.
-    "mov %ebp, %esp\n"
-    "pop %ebp\n"
-    "naclret");
-
-std::string TestNaClIRTStackAlignment::TestMisalignedCallVarAddRef() {
-  PP_Var var;
-  var.type = PP_VARTYPE_INT32;
-  var.padding = 0;
-  var.value.as_int = 23;
-
-  ASSERT_EQ(sizeof(var), static_cast<size_t>(16));
-
-  // This will crash if the test fails.
-  MisalignedCall(var_interface_->AddRef, &var);
-  MisalignedCall(var_interface_->Release, &var);
-
-  PASS();
-}
-
-#endif  // defined(__i386__)
diff --git a/ppapi/tests/test_nacl_irt_stack_alignment.h b/ppapi/tests/test_nacl_irt_stack_alignment.h
deleted file mode 100644
index 61de76f..0000000
--- a/ppapi/tests/test_nacl_irt_stack_alignment.h
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright (c) 2015 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.
-
-#ifndef PPAPI_TEST_TEST_NACL_IRT_STACK_ALIGNMENT_H_
-#define PPAPI_TEST_TEST_NACL_IRT_STACK_ALIGNMENT_H_
-
-#include <string>
-
-#include "ppapi/c/ppb_var.h"
-#include "ppapi/cpp/var.h"
-#include "ppapi/tests/test_case.h"
-
-class TestNaClIRTStackAlignment : public TestCase {
- public:
-  explicit TestNaClIRTStackAlignment(TestingInstance* instance)
-      : TestCase(instance) {}
-
- private:
-  // TestCase implementation.
-  virtual bool Init();
-  virtual void RunTests(const std::string& filter);
-
-  std::string TestMisalignedCallVarAddRef();
-
-  // Used by the tests that access the C API directly.
-  const PPB_Var* var_interface_;
-};
-
-#endif  // PPAPI_TEST_TEST_NACL_IRT_STACK_ALIGNMENT_H_