Bug 1312148 - report memory allocation while creating ImageBitmap; r=mtseng,smaug

Creating ImageBitmap from the following sources includes allocating new memory:
(1) from ImageData.
(2) from Blob.
(3) from HTMLCanvasElement.
(4) from CanvasRenderingContext2D.
(5) from Structured-clone.
(6) from Transferring.
(7) from OffscreenCanvas.
(8) from ArrayBuffer/TypedArray.

We need to report to DOM so that the GC would be triggered appropriately.

MozReview-Commit-ID: 7rvNsjVNqpz

--HG--
extra : rebase_source : 25760f91bd71fe2150fa3ae37dfc1fb8b53c15a4

dom/canvas/ImageBitmap.cpp

@@ -34,6 +34,19 @@ NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ImageBitmap)
   NS_INTERFACE_MAP_ENTRY(nsISupports)
 NS_INTERFACE_MAP_END
 
+/*
+ * This helper function is used to notify DOM that aBytes memory is allocated
+ * here so that we could trigger GC appropriately.
+ */
+static void
+RegisterAllocation(nsIGlobalObject* aGlobal, size_t aBytes)
+{
+  AutoJSAPI jsapi;
+  if (jsapi.Init(aGlobal)) {
+    JS_updateMallocCounter(jsapi.cx(), aBytes);
+  }
+}
+
 /*
  * If either aRect.width or aRect.height are negative, then return a new IntRect
  * which represents the same rectangle as the aRect does but with positive width
@@ -707,6 +720,9 @@ ImageBitmap::CreateFromCloneData(nsIGlobalObject* aGlobal,
   RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data,
                                             aData->mIsPremultipliedAlpha);
 
+  // Report memory allocation.
+  RegisterAllocation(aGlobal, ret->mDataWrapper->GetBufferLength());
+
   ret->mIsCroppingAreaOutSideOfSourceImage =
     aData->mIsCroppingAreaOutSideOfSourceImage;
 
@@ -741,6 +757,10 @@ ImageBitmap::CreateFromOffscreenCanvas(nsIGlobalObject* aGlobal,
     CreateImageFromSurface(surface);
 
   RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data);
+
+  // Report memory allocation.
+  RegisterAllocation(aGlobal, ret->mDataWrapper->GetBufferLength());
+
   return ret.forget();
 }
 
@@ -865,6 +885,7 @@ ImageBitmap::CreateInternal(nsIGlobalObject* aGlobal, HTMLCanvasElement& aCanvas
   // If the HTMLCanvasElement's rendering context is WebGL, then the snapshot
   // we got from the HTMLCanvasElement is a DataSourceSurface which is a copy
   // of the rendering context. We handle cropping in this case.
+  bool needToReportMemoryAllocation = false;
   if ((aCanvasEl.GetCurrentContextType() == CanvasContextType::WebGL1 ||
        aCanvasEl.GetCurrentContextType() == CanvasContextType::WebGL2) &&
       aCropRect.isSome()) {
@@ -875,6 +896,7 @@ ImageBitmap::CreateInternal(nsIGlobalObject* aGlobal, HTMLCanvasElement& aCanvas
     RefPtr<DataSourceSurface> dataSurface = surface->GetDataSurface();
     croppedSurface = CropAndCopyDataSourceSurface(dataSurface, cropRect);
     cropRect.MoveTo(0, 0);
+    needToReportMemoryAllocation = true;
   }
   else {
     croppedSurface = surface;
@@ -895,6 +917,11 @@ ImageBitmap::CreateInternal(nsIGlobalObject* aGlobal, HTMLCanvasElement& aCanvas
 
   RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data);
 
+  // Report memory allocation if needed.
+  if (needToReportMemoryAllocation) {
+    RegisterAllocation(aGlobal, ret->mDataWrapper->GetBufferLength());
+  }
+
   // Set the picture rectangle.
   if (ret && aCropRect.isSome()) {
     ret->SetPictureRect(cropRect, aRv);
@@ -958,6 +985,9 @@ ImageBitmap::CreateInternal(nsIGlobalObject* aGlobal, ImageData& aImageData,
   // ImageData's underlying data is not alpha-premultiplied.
   RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data, false);
 
+  // Report memory allocation.
+  RegisterAllocation(aGlobal, ret->mDataWrapper->GetBufferLength());
+
   // The cropping information has been handled in the CreateImageFromRawData()
   // function.
 
@@ -999,6 +1029,9 @@ ImageBitmap::CreateInternal(nsIGlobalObject* aGlobal, CanvasRenderingContext2D&
 
   RefPtr<ImageBitmap> ret = new ImageBitmap(aGlobal, data);
 
+  // Report memory allocation.
+  RegisterAllocation(aGlobal, ret->mDataWrapper->GetBufferLength());
+
   // Set the picture rectangle.
   if (ret && aCropRect.isSome()) {
     ret->SetPictureRect(aCropRect.ref(), aRv);
@@ -1240,6 +1273,9 @@ protected:
       }
     }
 
+    // Report memory allocation.
+    RegisterAllocation(mGlobalObject, imageBitmap->mDataWrapper->GetBufferLength());
+
     mPromise->MaybeResolve(imageBitmap);
     return true;
   }
@@ -1524,6 +1560,9 @@ ImageBitmap::ReadStructuredClone(JSContext* aCx,
     if (!GetOrCreateDOMReflector(aCx, imageBitmap, &value)) {
       return nullptr;
     }
+
+    // Report memory allocation.
+    RegisterAllocation(aParent, imageBitmap->mDataWrapper->GetBufferLength());
   }
 
   return &(value.toObject());
@@ -2112,6 +2151,9 @@ ImageBitmap::Create(nsIGlobalObject* aGlobal,
   // Assume the data from an external buffer is not alpha-premultiplied.
   RefPtr<ImageBitmap> imageBitmap = new ImageBitmap(aGlobal, data, false);
 
+  // Report memory allocation.
+  RegisterAllocation(aGlobal, imageBitmap->mDataWrapper->GetBufferLength());
+
   // We don't need to call SetPictureRect() here because there is no cropping
   // supported and the ImageBitmap's mPictureRect is the size of the source
   // image in default