Bug 1466613 - Add a gfxCriticalNote to provide more details on replay failure. r=jrmuizel

Differential Revision: https://phabricator.services.mozilla.com/D8257

--HG--
extra : moz-landing-system : lando

gfx/2d/InlineTranslator.cpp

@@ -56,18 +56,21 @@ InlineTranslator::TranslateRecording(char *aData, size_t aLen)
   uint32_t magicInt;
   ReadElement(reader, magicInt);
   if (magicInt != mozilla::gfx::kMagicInt) {
+    mError = "Magic";
     return false;
   }
 
   uint16_t majorRevision;
   ReadElement(reader, majorRevision);
   if (majorRevision != kMajorRevision) {
+    mError = "Major";
     return false;
   }
 
   uint16_t minorRevision;
   ReadElement(reader, minorRevision);
   if (minorRevision > kMinorRevision) {
+    mError = "Minor";
     return false;
   }
 
@@ -78,16 +81,19 @@ InlineTranslator::TranslateRecording(char *aData, size_t aLen)
                                [&] (RecordedEvent *recordedEvent) {
                                  // Make sure that the whole event was read from the stream successfully.
                                  if (!reader.good()) {
+                                     mError = " READ";
                                      return false;
                                  }
 
                                  if (!recordedEvent->PlayEvent(this)) {
+                                     mError = " PLAY";
                                      return false;
                                  }
 
                                  return true;
                               });
     if (!success) {
+      mError = RecordedEvent::GetEventName(static_cast<RecordedEvent::EventType>(eventType)) + mError;
       return false;
     }
 

gfx/2d/InlineTranslator.h

@@ -8,6 +8,7 @@
 #define mozilla_layout_InlineTranslator_h
 
 #include <istream>
+#include <string>
 
 #include "mozilla/gfx/2D.h"
 #include "mozilla/gfx/Filters.h"
@@ -184,10 +185,12 @@ public:
   mozilla::gfx::DrawTarget* GetReferenceDrawTarget() final { return mBaseDT; }
 
   void* GetFontContext() final { return mFontContext; }
+  std::string GetError() { return mError; }
 
 private:
   RefPtr<DrawTarget> mBaseDT;
   void*              mFontContext;
+  std::string        mError;
 
   nsRefPtrHashtable<nsPtrHashKey<void>, DrawTarget> mDrawTargets;
   nsRefPtrHashtable<nsPtrHashKey<void>, Path> mPaths;

gfx/webrender_bindings/Moz2DImageRenderer.cpp

@@ -445,7 +445,10 @@ static bool Moz2DRenderCallback(const Range<const uint8_t> aBlob,
 
     Range<const uint8_t> blob(aBlob.begin() + offset, aBlob.begin() + end);
     ret = translator.TranslateRecording((char*)blob.begin().get(), blob.length());
-    MOZ_RELEASE_ASSERT(ret);
+    if (!ret) {
+      gfxCriticalNote << "Replay failure: " << translator.GetError();
+      MOZ_RELEASE_ASSERT(false);
+    }
     offset = extra_end;
   }