content: Remove non-thread-safe use of WeakPtrs.

content/child/child_discardable_shared_memory_manager.cc

Index: content/child/child_discardable_shared_memory_manager.cc
diff --git a/content/child/child_discardable_shared_memory_manager.cc b/content/child/child_discardable_shared_memory_manager.cc
index 14dfe97e7df975420594e4de8ed44e358451f88d..e7a12ab87f1e45351e7674c6d55e766d02b75d46 100644
--- a/content/child/child_discardable_shared_memory_manager.cc
+++ b/content/child/child_discardable_shared_memory_manager.cc
@@ -71,17 +71,20 @@ class DiscardableMemoryImpl : public base::DiscardableMemory {
   DISALLOW_COPY_AND_ASSIGN(DiscardableMemoryImpl);
 };
 
+void SendDeletedDiscardableSharedMemoryMessage(
+    scoped_refptr<ThreadSafeSender> sender,
+    DiscardableSharedMemoryId id) {
+  sender->Send(new ChildProcessHostMsg_DeletedDiscardableSharedMemory(id));
+}
+
 }  // namespace
 
 ChildDiscardableSharedMemoryManager::ChildDiscardableSharedMemoryManager(
     ThreadSafeSender* sender)
-    : heap_(base::GetPageSize()), sender_(sender), weak_ptr_factory_(this) {
+    : heap_(base::GetPageSize()), sender_(sender) {
 }
 
 ChildDiscardableSharedMemoryManager::~ChildDiscardableSharedMemoryManager() {
-  // Cancel all DeletedDiscardableSharedMemory callbacks.
-  weak_ptr_factory_.InvalidateWeakPtrs();
-
   // TODO(reveman): Determine if this DCHECK can be enabled. crbug.com/430533
   // DCHECK_EQ(heap_.GetSize(), heap_.GetSizeOfFreeLists());
   if (heap_.GetSize())
@@ -167,9 +170,7 @@ ChildDiscardableSharedMemoryManager::AllocateLockedDiscardableMemory(
   // Create span for allocated memory.
   scoped_ptr<DiscardableSharedMemoryHeap::Span> new_span(heap_.Grow(
       shared_memory.Pass(), allocation_size_in_bytes,
-      base::Bind(
-          &ChildDiscardableSharedMemoryManager::DeletedDiscardableSharedMemory,
-          weak_ptr_factory_.GetWeakPtr(), new_id)));
+      base::Bind(&SendDeletedDiscardableSharedMemoryMessage, sender_, new_id)));
 
   // Unlock and insert any left over memory into free lists.
   if (pages < pages_to_allocate) {
@@ -271,11 +272,6 @@ ChildDiscardableSharedMemoryManager::AllocateLockedDiscardableSharedMemory(
   return memory.Pass();
 }
 
-void ChildDiscardableSharedMemoryManager::DeletedDiscardableSharedMemory(
-    DiscardableSharedMemoryId id) {
-  sender_->Send(new ChildProcessHostMsg_DeletedDiscardableSharedMemory(id));
-}
-
 void ChildDiscardableSharedMemoryManager::MemoryUsageChanged(
     size_t new_bytes_total,
     size_t new_bytes_free) const {