Bug 1267918 - Add GMPCrashHelper for MediaKeys. r=gerald

So if a GMP crashes while doing EME, we'll get a crash report using the new
mechanism.

MozReview-Commit-ID: G8BlFI9jmiF

--HG--
extra : rebase_source : 1cda5c93ea9e547636b34ec2149ef9cd2506ca73

dom/media/eme/CDMProxy.cpp

@@ -19,6 +19,7 @@
 #include "mozilla/CDMCallbackProxy.h"
 #include "MediaData.h"
 #include "nsPrintfCString.h"
+#include "GMPService.h"
 
 namespace mozilla {
 
@@ -43,7 +44,8 @@ CDMProxy::Init(PromiseId aPromiseId,
                const nsAString& aOrigin,
                const nsAString& aTopLevelOrigin,
                const nsAString& aGMPName,
-               bool aInPrivateBrowsing)
+               bool aInPrivateBrowsing,
+               GMPCrashHelper* aCrashHelper)
 {
   MOZ_ASSERT(NS_IsMainThread());
   NS_ENSURE_TRUE_VOID(!mKeys.IsNull());
@@ -82,6 +84,7 @@ CDMProxy::Init(PromiseId aPromiseId,
   data->mTopLevelOrigin = aTopLevelOrigin;
   data->mGMPName = aGMPName;
   data->mInPrivateBrowsing = aInPrivateBrowsing;
+  data->mCrashHelper = aCrashHelper;
   nsCOMPtr<nsIRunnable> task(
     NewRunnableMethod<nsAutoPtr<InitData>>(this,
                                            &CDMProxy::gmp_Init,
@@ -226,9 +229,12 @@ CDMProxy::gmp_InitGetGMPDecryptor(nsresult aResult,
   nsTArray<nsCString> tags;
   tags.AppendElement(NS_ConvertUTF16toUTF8(mKeySystem));
 
+  // Note: must capture helper refptr here, before the Move()
+  // when we create the GetGMPDecryptorCallback below.
+  RefPtr<GMPCrashHelper> crashHelper = Move(aData->mCrashHelper);
   UniquePtr<GetGMPDecryptorCallback> callback(new gmp_InitDoneCallback(this,
                                                                        Move(aData)));
-  nsresult rv = mps->GetGMPDecryptor(nullptr, &tags, GetNodeId(), Move(callback));
+  nsresult rv = mps->GetGMPDecryptor(crashHelper, &tags, GetNodeId(), Move(callback));
   if (NS_FAILED(rv)) {
     RejectPromise(promiseID, NS_ERROR_DOM_INVALID_STATE_ERR,
                   NS_LITERAL_CSTRING("Call to GetGMPDecryptor() failed early"));

dom/media/eme/CDMProxy.h

@@ -58,7 +58,8 @@ public:
             const nsAString& aOrigin,
             const nsAString& aTopLevelOrigin,
             const nsAString& aGMPName,
-            bool aInPrivateBrowsing);
+            bool aInPrivateBrowsing,
+            GMPCrashHelper* aHelper);
 
   // Main thread only.
   // Uses the CDM to create a key session.
@@ -188,6 +189,7 @@ private:
     nsString mOrigin;
     nsString mTopLevelOrigin;
     nsString mGMPName;
+    RefPtr<GMPCrashHelper> mCrashHelper;
     bool mInPrivateBrowsing;
   };
 

dom/media/eme/MediaKeys.cpp

@@ -284,6 +284,26 @@ MediaKeys::ResolvePromise(PromiseId aId)
   MOZ_ASSERT(!mPromises.Contains(aId));
 }
 
+class MediaKeysGMPCrashHelper : public GMPCrashHelper
+{
+public:
+  explicit MediaKeysGMPCrashHelper(MediaKeys* aMediaKeys)
+    : mMediaKeys(aMediaKeys)
+  {
+    MOZ_ASSERT(NS_IsMainThread()); // WeakPtr isn't thread safe.
+  }
+  already_AddRefed<nsPIDOMWindowInner>
+  GetPluginCrashedEventTarget() override
+  {
+    MOZ_ASSERT(NS_IsMainThread()); // WeakPtr isn't thread safe.
+    EME_LOG("MediaKeysGMPCrashHelper::GetPluginCrashedEventTarget()");
+    return (mMediaKeys && mMediaKeys->GetParentObject()) ?
+      do_AddRef(mMediaKeys->GetParentObject()) : nullptr;
+  }
+private:
+  WeakPtr<MediaKeys> mMediaKeys;
+};
+
 already_AddRefed<DetailedPromise>
 MediaKeys::Init(ErrorResult& aRv)
 {
@@ -367,7 +387,8 @@ MediaKeys::Init(ErrorResult& aRv)
                origin,
                topLevelOrigin,
                KeySystemToGMPName(mKeySystem),
-               inPrivateBrowsing);
+               inPrivateBrowsing,
+               new MediaKeysGMPCrashHelper(this));
 
   return promise.forget();
 }

dom/media/eme/MediaKeys.h

@@ -19,6 +19,7 @@
 #include "mozilla/dom/MediaKeysBinding.h"
 #include "mozIGeckoMediaPluginService.h"
 #include "mozilla/DetailedPromise.h"
+#include "mozilla/WeakPtr.h"
 
 namespace mozilla {
 
@@ -36,15 +37,17 @@ typedef nsRefPtrHashtable<nsUint32HashKey, MediaKeySession> PendingKeySessionsHa
 typedef uint32_t PromiseId;
 
 // This class is used on the main thread only.
-// Note: it's addref/release is not (and can't be) thread safe!
+// Note: its addref/release is not (and can't be) thread safe!
 class MediaKeys final : public nsISupports,
-                        public nsWrapperCache
+                        public nsWrapperCache,
+                        public SupportsWeakPtr<MediaKeys>
 {
   ~MediaKeys();
 
 public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(MediaKeys)
+  MOZ_DECLARE_WEAKREFERENCE_TYPENAME(MediaKeys)
 
   MediaKeys(nsPIDOMWindowInner* aParentWindow,
             const nsAString& aKeySystem, const nsAString& aCDMVersion);