Create and pass shared-histogram-allocator from browser to renderer.

base/metrics/persistent_histogram_allocator.cc

 // Copyright 2016 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/persistent_histogram_allocator.h"
 
 #include <memory>
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 462 matching lines @@
   Set(WrapUnique(new GlobalHistogramAllocator(
       WrapUnique(new LocalPersistentMemoryAllocator(size, id, name)))));
 }
 
 // static
 void GlobalHistogramAllocator::CreateWithSharedMemory(
     std::unique_ptr<SharedMemory> memory,
     size_t size,
     uint64_t id,
     StringPiece name) {
-  if (!memory->memory() && !memory->Map(size))
+  if ((!memory->memory() && !memory->Map(size)) ||
+      !SharedPersistentMemoryAllocator::IsSharedMemoryAcceptable(*memory)) {
     NOTREACHED();
+    return;
+  }
 
-  if (memory->memory()) {
-    DCHECK_LE(memory->mapped_size(), size);
-    Set(WrapUnique(new GlobalHistogramAllocator(
-        WrapUnique(new SharedPersistentMemoryAllocator(
-            std::move(memory), 0, StringPiece(), /*readonly=*/false)))));
-  }
+  DCHECK_LE(memory->mapped_size(), size);
+  Set(WrapUnique(new GlobalHistogramAllocator(
+      WrapUnique(new SharedPersistentMemoryAllocator(
+          std::move(memory), 0, StringPiece(), /*readonly=*/false)))));
 }
 
 // static
 void GlobalHistogramAllocator::CreateWithSharedMemoryHandle(
     const SharedMemoryHandle& handle,
     size_t size) {
   std::unique_ptr<SharedMemory> shm(
       new SharedMemory(handle, /*readonly=*/false));
-  if (!shm->Map(size)) {
+  if (!shm->Map(size) ||
+      !SharedPersistentMemoryAllocator::IsSharedMemoryAcceptable(*shm)) {
     NOTREACHED();
     return;
   }
 
   Set(WrapUnique(new GlobalHistogramAllocator(
       WrapUnique(new SharedPersistentMemoryAllocator(
           std::move(shm), 0, StringPiece(), /*readonly=*/false)))));
 }
 
 // static
@@ skipping 69 matching lines @@
   while (true) {
     std::unique_ptr<HistogramBase> histogram =
         import_iterator_.GetNextWithIgnore(record_to_ignore);
     if (!histogram)
       break;
     StatisticsRecorder::RegisterOrDeleteDuplicate(histogram.release());
   }
 }
 
 }  // namespace base