Bug 1366097 - Part 3. Implement VectorImage::GetImageContainerAtSize and VectorImage::IsImageContainerAvailableAtSize. r=tnikkel

This is largely trivial because the meat of the implementation is
located in ImageResource and we already added GetFrameInternal.
Interestingly VectorImage::IsUnlocked does not actually check if the
image is locked, but instead only checks for animation consumers. This
is consistent with its historical behavior on when to issue an unlocked
draw event.

Note that we do not implement the original GetImageContainer and
IsImageContainerAvailable APIs. This is because the former does not
accept an SVG context and it would be best to discourage its use in old
code lest we get incorrect/unexpected results.

Author: aosmond

image/VectorImage.cpp

@@ -15,6 +15,7 @@
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/dom/SVGSVGElement.h"
 #include "mozilla/gfx/2D.h"
+#include "mozilla/gfx/gfxVars.h"
 #include "mozilla/RefPtr.h"
 #include "mozilla/Tuple.h"
 #include "nsIDOMEvent.h"
@@ -583,6 +584,8 @@ VectorImage::SendInvalidationNotifications()
     mProgressTracker->SyncNotifyProgress(FLAG_FRAME_COMPLETE,
                                          GetMaxSizedIntRect());
   }
+
+  UpdateImageContainer();
 }
 
 NS_IMETHODIMP_(IntRect)
@@ -801,6 +804,18 @@ VectorImage::GetFrameInternal(const IntSize& aSize,
 }
 
 //******************************************************************************
+IntSize
+VectorImage::GetImageContainerSize(LayerManager* aManager,
+                                   const IntSize& aSize,
+                                   uint32_t aFlags)
+{
+  if (!IsImageContainerAvailableAtSize(aManager, aSize, aFlags)) {
+    return IntSize(0, 0);
+  }
+
+  return aSize;
+}
+
 NS_IMETHODIMP_(bool)
 VectorImage::IsImageContainerAvailable(LayerManager* aManager, uint32_t aFlags)
 {
@@ -820,7 +835,14 @@ VectorImage::IsImageContainerAvailableAtSize(LayerManager* aManager,
                                              const IntSize& aSize,
                                              uint32_t aFlags)
 {
-  return false;
+  if (mError || !mIsFullyLoaded || aSize.IsEmpty() ||
+      mHaveAnimations || !gfxVars::UseWebRender()) {
+    return false;
+  }
+
+  int32_t maxTextureSize = aManager->GetMaxTextureSize();
+  return aSize.width <= maxTextureSize &&
+         aSize.height <= maxTextureSize;
 }
 
 //******************************************************************************
@@ -829,7 +851,10 @@ VectorImage::GetImageContainerAtSize(LayerManager* aManager,
                                      const IntSize& aSize,
                                      uint32_t aFlags)
 {
-  return nullptr;
+  // Since we do not support high quality scaling with SVG, we mask it off so
+  // that container requests with and without it map to the same container.
+  uint32_t flags = aFlags & ~FLAG_HIGH_QUALITY_SCALING;
+  return GetImageContainerImpl(aManager, aSize, aFlags);
 }
 
 //******************************************************************************

image/VectorImage.h

@@ -86,6 +86,10 @@ class VectorImage final : public ImageResource,
                      uint32_t aWhichFrame,
                      uint32_t aFlags) override;
 
+  IntSize GetImageContainerSize(layers::LayerManager* aManager,
+                                const IntSize& aSize,
+                                uint32_t aFlags) override;
+
   /// Attempt to find a matching cached surface in the SurfaceCache.
   already_AddRefed<SourceSurface>
     LookupCachedSurface(const IntSize& aSize,