Update from https://crrev.com/306706

Includes formatted BUILD.gn files and a buildtools rev new enough to
run gn format ourselves.

Review URL: https://codereview.chromium.org/773373002
diff --git a/cc/resources/picture.cc b/cc/resources/picture.cc
index 5b90571..6530866 100644
--- a/cc/resources/picture.cc
+++ b/cc/resources/picture.cc
@@ -175,17 +175,13 @@
     TRACE_DISABLED_BY_DEFAULT("cc.debug"), "cc::Picture", this);
 }
 
-bool Picture::IsSuitableForGpuRasterization() const {
+bool Picture::IsSuitableForGpuRasterization(const char** reason) const {
   DCHECK(picture_);
 
-  // TODO(alokp): SkPicture::suitableForGpuRasterization needs a GrContext.
-  // Ideally this GrContext should be the same as that for rasterizing this
-  // picture. But we are on the main thread while the rasterization context
-  // may be on the compositor or raster thread.
-  // SkPicture::suitableForGpuRasterization is not implemented yet.
-  // Pass a NULL context for now and discuss with skia folks if the context
-  // is really needed.
-  return picture_->suitableForGpuRasterization(NULL);
+  // TODO(hendrikw): SkPicture::suitableForGpuRasterization takes a GrContext.
+  // Currently the GrContext isn't used, and should probably be removed from
+  // skia.
+  return picture_->suitableForGpuRasterization(nullptr, reason);
 }
 
 int Picture::ApproximateOpCount() const {