Sandbox: Remove raw handles from PolicyBase.

sandbox/win/src/sandbox_policy_base.cc

Index: sandbox/win/src/sandbox_policy_base.cc
diff --git a/sandbox/win/src/sandbox_policy_base.cc b/sandbox/win/src/sandbox_policy_base.cc
index 6df2cb3d3819d33c2e742efdc441192de16ca996..482172cb75be9bcb961c9ba1d6d680edd75fb4f0 100644
--- a/sandbox/win/src/sandbox_policy_base.cc
+++ b/sandbox/win/src/sandbox_policy_base.cc
@@ -9,6 +9,7 @@
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/logging.h"
+#include "base/stl_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/win/windows_version.h"
 #include "sandbox/win/src/app_container.h"
@@ -466,33 +467,26 @@ ResultCode PolicyBase::AddKernelObjectToClose(const base::char16* handle_type,
 
 void* PolicyBase::AddHandleToShare(HANDLE handle) {
   if (base::win::GetVersion() < base::win::VERSION_VISTA)
-    return NULL;
+    return nullptr;
 
   if (!handle)
-    return NULL;
+    return nullptr;
 
-  HANDLE duped_handle = NULL;
-  ::DuplicateHandle(::GetCurrentProcess(),
-                    handle,
-                    ::GetCurrentProcess(),
-                    &duped_handle,
-                    0,
-                    TRUE,
-                    DUPLICATE_SAME_ACCESS);
-  DCHECK(duped_handle);
-  handles_to_share_.push_back(duped_handle);
+  HANDLE duped_handle = nullptr;
+  if (!::DuplicateHandle(::GetCurrentProcess(), handle, ::GetCurrentProcess(),
+                         &duped_handle, 0, TRUE, DUPLICATE_SAME_ACCESS)) {
+    return nullptr;
+  }
+  handles_to_share_.push_back(new base::win::ScopedHandle(duped_handle));

[Will Harris, 2015/07/10 18:05:02]

this is a behavior change, previously we'd push a NULL handle, but it doesn't
seem to actually change any real behavior.

[rvargas (doing something else), 2015/07/10 18:26:45]

Correct, but judging by the (insufficient) dcheck, that was actually a bug
because it was unintended. 

   return duped_handle;
 }
 
-HandleList PolicyBase::GetHandlesBeingShared() {
+const HandleList& PolicyBase::GetHandlesBeingShared() {
   return handles_to_share_;
 }
 
 void PolicyBase::ClearSharedHandles() {
-  for (auto handle : handles_to_share_) {
-    ::CloseHandle(handle);
-  }
-  handles_to_share_.clear();
+  STLDeleteElements(&handles_to_share_);
 }
 
 // When an IPC is ready in any of the targets we get called. We manage an array