Add crash keys about field trial shared memory errors.

base/metrics/field_trial.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 "base/metrics/field_trial.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/base_switches.h"
 #include "base/build_time.h"
 #include "base/command_line.h"
 #include "base/debug/activity_tracker.h"
+#include "base/debug/crash_logging.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial_param_associator.h"
 #include "base/process/memory.h"
 #include "base/rand_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/unguessable_token.h"
 
@@ skipping 1199 matching lines @@
     return;
 
   SharedMemoryCreateOptions options;
   options.size = kFieldTrialAllocationSize;
   options.share_read_only = true;
 #if defined(OS_MACOSX) && !defined(OS_IOS)
   options.type = SharedMemoryHandle::POSIX;
 #endif
 
   std::unique_ptr<SharedMemory> shm(new SharedMemory());
-  if (!shm->Create(options))
+  if (!shm->Create(options)) {
+#if !defined(OS_NACL)
+    // Temporary for http://crbug.com/703649.
+    base::debug::ScopedCrashKey crash_key(
+        "field_trial_shmem_create_error",
+        base::IntToString(static_cast<int>(shm->get_last_error())));
+#endif
     OnOutOfMemory(kFieldTrialAllocationSize);
+  }
 
-  if (!shm->Map(kFieldTrialAllocationSize))
+  if (!shm->Map(kFieldTrialAllocationSize)) {
+#if !defined(OS_NACL)
+    // Temporary for http://crbug.com/703649.
+    base::debug::ScopedCrashKey crash_key(
+        "field_trial_shmem_map_error",
+        base::IntToString(static_cast<int>(shm->get_last_error())));
+#endif
     OnOutOfMemory(kFieldTrialAllocationSize);
+  }
 
   global_->field_trial_allocator_.reset(
       new FieldTrialAllocator(std::move(shm), 0, kAllocatorName, false));
   global_->field_trial_allocator_->CreateTrackingHistograms(kAllocatorName);
 
   // Add all existing field trials.
   for (const auto& registered : global_->registered_) {
     AddToAllocatorWhileLocked(global_->field_trial_allocator_.get(),
                               registered.second);
   }
@@ skipping 111 matching lines @@
     return;
   }
   AutoLock auto_lock(global_->lock_);
   CHECK(!global_->PreLockedFind(trial->trial_name())) << trial->trial_name();
   trial->AddRef();
   trial->SetTrialRegistered();
   global_->registered_[trial->trial_name()] = trial;
 }
 
 }  // namespace base