Make the new Mojo EDK work on XP.

mojo/edk/embedder/simple_platform_shared_buffer_unittest.cc

 // Copyright 2014 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 "mojo/edk/embedder/simple_platform_shared_buffer.h"
 
 #include <limits>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/sys_info.h"
 #include "mojo/public/cpp/system/macros.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#if defined(OS_WIN)
+#include "base/win/windows_version.h"
+#endif
+
 namespace mojo {
 namespace edk {
 namespace {
 
 TEST(SimplePlatformSharedBufferTest, Basic) {
   const size_t kNumInts = 100;
   const size_t kNumBytes = kNumInts * sizeof(int);
   // A fudge so that we're not just writing zero bytes 75% of the time.
   const int kFudge = 1234567890;
 
@@ skipping 97 matching lines @@
   // Offset + length too big.
   EXPECT_FALSE(buffer->Map(50, 51));
   EXPECT_FALSE(buffer->IsValidMap(50, 51));
   EXPECT_FALSE(buffer->Map(51, 50));
   EXPECT_FALSE(buffer->IsValidMap(51, 50));
 }
 
 TEST(SimplePlatformSharedBufferTest, TooBig) {
   // If |size_t| is 32-bit, it's quite possible/likely that |Create()| succeeds
   // (since it only involves creating a 4 GB file).
-  const size_t kMaxSizeT = std::numeric_limits<size_t>::max();
+  size_t max_size = std::numeric_limits<size_t>::max();
+  if (max_size > static_cast<size_t>(base::SysInfo::AmountOfVirtualMemory()))
+    max_size = static_cast<size_t>(base::SysInfo::AmountOfVirtualMemory());
   scoped_refptr<SimplePlatformSharedBuffer> buffer(
-      SimplePlatformSharedBuffer::Create(kMaxSizeT));
+      SimplePlatformSharedBuffer::Create(max_size));
   // But, assuming |sizeof(size_t) == sizeof(void*)|, mapping all of it should
   // always fail.
   if (buffer)
-    EXPECT_FALSE(buffer->Map(0, kMaxSizeT));
+    EXPECT_FALSE(buffer->Map(0, max_size));
 }
 
 // Tests that separate mappings get distinct addresses.
 // Note: It's not inconceivable that the OS could ref-count identical mappings
 // and reuse the same address, in which case we'd have to be more careful about
 // using the address as the key for unmapping.
 TEST(SimplePlatformSharedBufferTest, MappingsDistinct) {
   scoped_refptr<SimplePlatformSharedBuffer> buffer(
       SimplePlatformSharedBuffer::Create(100));
   scoped_ptr<PlatformSharedBufferMapping> mapping1(buffer->Map(0, 100));
@@ skipping 30 matching lines @@
 
   EXPECT_EQ('x', static_cast<char*>(mapping2->GetBase())[0]);
 
   static_cast<char*>(mapping2->GetBase())[1] = 'y';
   EXPECT_EQ('y', static_cast<char*>(mapping1->GetBase())[51]);
 }
 
 }  // namespace
 }  // namespace edk
 }  // namespace mojo