Move GrBackendRenderTarget over to new system of getting backed infos

Bug: skia:
Change-Id: I3927390894715e8424b3d0240dad3ee6cd03dc38
Reviewed-on: https://skia-review.googlesource.com/120181
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/vk/GrVkCaps.cpp b/src/gpu/vk/GrVkCaps.cpp
index 5747cc0..ae1570c 100644
--- a/src/gpu/vk/GrVkCaps.cpp
+++ b/src/gpu/vk/GrVkCaps.cpp
@@ -510,12 +510,12 @@
 
 bool GrVkCaps::validateBackendRenderTarget(const GrBackendRenderTarget& rt, SkColorType ct,
                                            GrPixelConfig* config) const {
-    const GrVkImageInfo* imageInfo = rt.getVkImageInfo();
-    if (!imageInfo) {
+    GrVkImageInfo imageInfo;
+    if (!rt.getVkImageInfo(&imageInfo)) {
         return false;
     }
 
-    return validate_image_info(imageInfo->fFormat, ct, config);
+    return validate_image_info(imageInfo.fFormat, ct, config);
 }
 
 bool GrVkCaps::getConfigFromBackendFormat(const GrBackendFormat& format, SkColorType ct,