Fix crash in ImageLayerBridge on gpu resource allocation failure

BUG=847725

Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: Ie762af63cd0a414a10a940344b90e6296dcb60a9
Reviewed-on: https://chromium-review.googlesource.com/1093161
Commit-Queue: Justin Novosad <junov@chromium.org>
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566020}

third_party/blink/renderer/platform/graphics/accelerated_static_bitmap_image.h

@@ -44,8 +44,7 @@ class PLATFORM_EXPORT AcceleratedStaticBitmapImage final
   scoped_refptr<StaticBitmapImage> MakeAccelerated(
       base::WeakPtr<WebGraphicsContext3DProviderWrapper> context_wrapper)
       override {
-    NOTREACHED();  // IsTextureBacked() is already true.
-    return nullptr;
+    return this;
   }
 
   void Draw(PaintCanvas*,

third_party/blink/renderer/platform/graphics/gpu/image_layer_bridge.cc

@@ -108,20 +108,12 @@ bool ImageLayerBridge::PrepareTransferableResource(
   // flipped.
   layer_->SetFlipped(gpu_image);
 
-  scoped_refptr<StaticBitmapImage> image_for_compositor;
-
-  // Upload to a texture if the compositor is expecting one.
-  if (gpu_compositing && !image_->IsTextureBacked()) {
-    image_for_compositor =
+  if (gpu_compositing) {
+    scoped_refptr<StaticBitmapImage> image_for_compositor =
         image_->MakeAccelerated(SharedGpuContext::ContextProviderWrapper());
-  } else if (!gpu_compositing && image_->IsTextureBacked()) {
-    image_for_compositor = image_->MakeUnaccelerated();
-  } else {
-    image_for_compositor = image_;
-  }
-  DCHECK_EQ(image_for_compositor->IsTextureBacked(), gpu_compositing);
+    if (!image_for_compositor)
+      return false;
 
-  if (gpu_compositing) {
     uint32_t filter =
         filter_quality_ == kNone_SkFilterQuality ? GL_NEAREST : GL_LINEAR;
     image_for_compositor->EnsureMailbox(kUnverifiedSyncToken, filter);
@@ -133,13 +125,17 @@ bool ImageLayerBridge::PrepareTransferableResource(
                   WrapWeakPersistent(this), std::move(image_for_compositor));
     *out_release_callback = viz::SingleReleaseCallback::Create(std::move(func));
   } else {
-    sk_sp<SkImage> sk_image =
-        image_for_compositor->PaintImageForCurrentFrame().GetSkImage();
+    // Readback if needed and retain the readback in image_ to prevent future
+    // readbacks
+    image_ = image_->MakeUnaccelerated();
+    if (!image_)
+      return false;
+
+    sk_sp<SkImage> sk_image = image_->PaintImageForCurrentFrame().GetSkImage();
     if (!sk_image)
       return false;
 
-    const gfx::Size size(image_for_compositor->width(),
-                         image_for_compositor->height());
+    const gfx::Size size(image_->width(), image_->height());
     viz::ResourceFormat resource_format = viz::RGBA_8888;
     if (sk_image->colorType() == SkColorType::kRGBA_F16_SkColorType)
       resource_format = viz::RGBA_F16;