Set the "mutable format" bit on sRGB images at creation time.

src/gpu/vk/GrVkImage.cpp

Index: src/gpu/vk/GrVkImage.cpp
diff --git a/src/gpu/vk/GrVkImage.cpp b/src/gpu/vk/GrVkImage.cpp
index 9e7faf4706e9ef0f3d7441f163df6a325e9b60d8..d3195e7e8a0a9f41c6f96fe842e7b69aef471b65 100644
--- a/src/gpu/vk/GrVkImage.cpp
+++ b/src/gpu/vk/GrVkImage.cpp
@@ -77,10 +77,14 @@ bool GrVkImage::InitImageInfo(const GrVkGpu* gpu, const ImageDesc& imageDesc, Gr
     SkASSERT(VK_IMAGE_TILING_OPTIMAL == imageDesc.fImageTiling ||
              VK_SAMPLE_COUNT_1_BIT == vkSamples);
 
+    // sRGB format images may need to be aliased to linear for various reasons (legacy mode):
+    VkImageCreateFlags createFlags = GrVkFormatIsSRGB(imageDesc.fFormat, nullptr)
+        ? VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT : 0;
+
     const VkImageCreateInfo imageCreateInfo = {
         VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO,         // sType
         NULL,                                        // pNext
-        0,                                           // VkImageCreateFlags
+        createFlags,                                 // VkImageCreateFlags
         imageDesc.fImageType,                        // VkImageType
         imageDesc.fFormat,                           // VkFormat
         { imageDesc.fWidth, imageDesc.fHeight, 1 },  // VkExtent3D