Added errno (or GetLastError code) to crash dump when systemAllocPages fails.

third_party/WebKit/Source/wtf/Partitions.cpp

Index: third_party/WebKit/Source/wtf/Partitions.cpp
diff --git a/third_party/WebKit/Source/wtf/Partitions.cpp b/third_party/WebKit/Source/wtf/Partitions.cpp
index b0e587de8d3639e4a85ff7feb4c3b70274bf787a..71b759291eead80ed544b5cf08ef6256eee9bd90 100644
--- a/third_party/WebKit/Source/wtf/Partitions.cpp
+++ b/third_party/WebKit/Source/wtf/Partitions.cpp
@@ -187,7 +187,7 @@ static NEVER_INLINE void partitionsOutOfMemoryUsing16M()
 
 static NEVER_INLINE void partitionsOutOfMemoryUsingLessThan16M()
 {
-    size_t signature = 16 * 1024 * 1024 - 1;
+    uint32_t signature = getAllocPageErrorCode();
     base::debug::Alias(&signature);

[sof, 2016/02/23 07:27:25]

If Alias() makes its (aliased) local variable persisted in minidumps, then
perhaps it would make sense to add this use of Alias() one level up to
handleOutOfMemory() ?

[tasak, 2016/02/24 03:53:33]

I see.
Done.

     IMMEDIATE_CRASH();
 }