Added budget_service.mojom

third_party/WebKit/Source/modules/budget/BudgetService.h

 // 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.
 
 #ifndef BudgetService_h
 #define BudgetService_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "modules/ModulesExport.h"
+#include "public/platform/modules/budget_service/budget_service.mojom-blink.h"
 
 namespace blink {
 
 class ScriptPromise;
+class ScriptPromiseResolver;
 class ScriptState;
 
 // This is the entry point into the browser for the BudgetService API, which is
 // designed to give origins the ability to perform background operations
 // on the user's behalf.
-class BudgetService final : public GarbageCollected<BudgetService>, public ScriptWrappable {
+class BudgetService final : public GarbageCollectedFinalized<BudgetService>, public ScriptWrappable {

[johnme, 2016/08/17 13:54:02]

Why does this need to be Finalized?

[harkness, 2016/08/18 10:23:26]

m_service requires it.

[johnme, 2016/08/18 13:04:31]

Some Mojo consumers reset their InterfacePtrs when the execution context is
destroyed (e.g. USB::contextDestroyed), or the mojo connection fails (e.g.
USB::on*ConnectionError, which also rejects the promises). Do either of those
apply here?

[harkness, 2016/08/22 08:57:47]

It appears that mojo Ptrs can't be traced using the oilpan lifecycle tracing, so
using that mechanism is out. When I try to compile without Finalized, I get an
explicit compiler error that m_service requires finalization, which I'm guessing
is because it's a mojo service. Looking at the InterfacePtr in mojo, it closes
the message pipe on destruction, so I suspect that destructor invocation is
being enforced by requiring Finalized.

[johnme, 2016/08/22 13:14:37]

Yes, my question is whether we should be cleaning it up earlier, rather than
leaving it active in a potentially invalid state. I'm not an expert here, but I
know that there are subtleties.

     DEFINE_WRAPPERTYPEINFO();
 
 public:
     static BudgetService* create()
     {
         return new BudgetService();
     }
 
+    ~BudgetService();
+
+    // Implementation of the Budget API interface.
     ScriptPromise getCost(ScriptState*, const AtomicString& actionType);
     ScriptPromise getBudget(ScriptState*);
 
+    // Callbacks from the BudgetService to the blink layer.
+    void asyncGetCost(ScriptPromiseResolver*, double) const;

[johnme, 2016/08/17 13:54:02]

Nit: gotCost or onGetCost?

[harkness, 2016/08/18 10:23:26]

Normally I hesititate on just changing verb tense, because I find it leads to
strange namings, but this one does seem pretty straightforward.

+    void asyncGetBudget(PassRefPtr<ScriptState>, ScriptPromiseResolver*, const mojo::WTFArray<mojom::blink::BudgetStatePtr>) const;
+
     DEFINE_INLINE_TRACE() {}
 
 private:
     BudgetService();
+
+    // Pointer to the Mojo service which will proxy calls to the browser.
+    mojom::blink::BudgetServicePtr m_service;
 };
 
 } // namespace blink
 
 #endif // BudgetService_h