DCHECK that |ptr| is valid when creating WeakPtrFactory

We already DCHECK that |ptr_| is valid in GetWeakPtr(), but this extra
check ensures we catch mis-use earlier.

Change-Id: Id62dc3cbe6c4e33f08bb1d5c5c2e304aa01c53a8
Reviewed-on: https://chromium-review.googlesource.com/1042485Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556346}

base/memory/weak_ptr.cc

@@ -70,9 +70,13 @@ WeakPtrBase::WeakPtrBase() : ptr_(0) {}
 WeakPtrBase::~WeakPtrBase() = default;
 
 WeakPtrBase::WeakPtrBase(const WeakReference& ref, uintptr_t ptr)
-    : ref_(ref), ptr_(ptr) {}
+    : ref_(ref), ptr_(ptr) {
+  DCHECK(ptr_);
+}
 
-WeakPtrFactoryBase::WeakPtrFactoryBase(uintptr_t ptr) : ptr_(ptr) {}
+WeakPtrFactoryBase::WeakPtrFactoryBase(uintptr_t ptr) : ptr_(ptr) {
+  DCHECK(ptr_);
+}
 
 WeakPtrFactoryBase::~WeakPtrFactoryBase() {
   ptr_ = 0;

base/memory/weak_ptr.h

@@ -307,7 +307,6 @@ class WeakPtrFactory : public internal::WeakPtrFactoryBase {
   ~WeakPtrFactory() = default;
 
   WeakPtr<T> GetWeakPtr() {
-    DCHECK(ptr_);
     return WeakPtr<T>(weak_reference_owner_.GetRef(),
                       reinterpret_cast<T*>(ptr_));
   }

extensions/browser/api/declarative/rules_registry.cc

@@ -87,7 +87,7 @@ RulesRegistry::RulesRegistry(content::BrowserContext* browser_context,
       ready_(/*signaled=*/!cache_delegate),  // Immediately ready if no cache
                                              // delegate to wait for.
       last_generated_rule_identifier_id_(0),
-      weak_ptr_factory_(browser_context_ ? this : NULL) {
+      weak_ptr_factory_(this) {
   if (cache_delegate) {
     cache_delegate_ = cache_delegate->GetWeakPtr();
     cache_delegate->Init(this);