Bug 1216366: Ensure D3D11 uploads the entire surface the first time for component alpha textures. r=nical

gfx/layers/d3d11/TextureD3D11.cpp

@@ -1018,6 +1018,7 @@ DataTextureSourceD3D11::Update(DataSourceSurface* aSurface,
       }
     }
 
+    nsIntRegion *regionToUpdate = aDestRegion;
     if (!mTexture) {
       hr = mCompositor->GetDevice()->CreateTexture2D(&desc, nullptr, getter_AddRefs(mTexture));
       mIsTiled = false;
@@ -1025,6 +1026,10 @@ DataTextureSourceD3D11::Update(DataSourceSurface* aSurface,
         Reset();
         return false;
       }
+
+      if (mFlags & TextureFlags::COMPONENT_ALPHA) {
+        regionToUpdate = nullptr;
+      }
     }
 
     DataSourceSurface::MappedSurface map;
@@ -1034,8 +1039,8 @@ DataTextureSourceD3D11::Update(DataSourceSurface* aSurface,
       return false;
     }
 
-    if (aDestRegion) {
-      nsIntRegionRectIterator iter(*aDestRegion);
+    if (regionToUpdate) {
+      nsIntRegionRectIterator iter(*regionToUpdate);
       const IntRect *iterRect;
       while ((iterRect = iter.Next())) {
         D3D11_BOX box;