PPAPI: Implement PPB_FileMapping on POSIX

ppapi/thunk/enter.cc

 // Copyright (c) 2012 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/thunk/enter.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/stringprintf.h"
@@ skipping 41 matching lines @@
     : resource_(GetResource(resource)),
       retval_(PP_OK) {
   callback_ = new TrackedCallback(resource_, callback);
   PpapiGlobals::Get()->MarkPluginIsActive();
 }
 
 EnterBase::EnterBase(PP_Instance instance, SingletonResourceID resource_id,
                      const PP_CompletionCallback& callback)
     : resource_(GetSingletonResource(instance, resource_id)),
       retval_(PP_OK) {
-  DCHECK(resource_ || !instance);

[teravest, 2014/01/23 21:40:58]

Why is this removed?

[dmichael (off chromium), 2014/01/24 20:02:50]

This case happens for singleton resources if you pass a bad resource, we just
had never tested that before. See the "Bad instance" part of my test; I pass
"PP_Instance(0xbadbad)", and expect to get a PP_ERROR_BADARGUMENT when the
instance can't be found. Instead, it was crashing in Debug because of this
DCHECK. (GetSingletonResource returns a NULL resource_, and instance is
non-zero).

   if (!resource_)
     retval_ = PP_ERROR_BADARGUMENT;
   callback_ = new TrackedCallback(resource_, callback);
   PpapiGlobals::Get()->MarkPluginIsActive();
 }
 
 EnterBase::~EnterBase() {
   // callback_ is cleared any time it is run, scheduled to be run, or once we
   // know it will be completed asynchronously. So by this point it should be
   // NULL.
@@ skipping 237 matching lines @@
     : EnterBase(),
       functions_(PpapiGlobals::Get()->GetResourceCreationAPI(instance)) {
   SetStateForFunctionError(instance, functions_, true);
 }
 
 EnterResourceCreationNoLock::~EnterResourceCreationNoLock() {
 }
 
 }  // namespace thunk
 }  // namespace ppapi