Revert "Remove setting/use of GrPixelConfig in GrBackendTex/RT ctors."

This reverts commit ff2181e62e79ffd2ce628fc8c05b5457d4f54163.

Reason for revert: suspect it's behind Chrome roll failure

Original change's description:
> Remove setting/use of GrPixelConfig in GrBackendTex/RT ctors.
> 
> Bug: skia:
> Change-Id: I1466668e3502cd1e6e1f6aed4105e0f626d293dd
> Reviewed-on: https://skia-review.googlesource.com/138987
> Commit-Queue: Greg Daniel <egdaniel@google.com>
> Reviewed-by: Robert Phillips <robertphillips@google.com>

TBR=egdaniel@google.com,bsalomon@google.com,robertphillips@google.com

Change-Id: I4cba44858aafffbadc45e18349b93c741d7cfc66
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/139220
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>

3 files changed, 41 insertions, 10 deletions

diff --git a/src/gpu/vk/GrVkGpu.cpp b/src/gpu/vk/GrVkGpu.cpp
index ed45c55758..ba1f7caf2d 100644
--- a/src/gpu/vk/GrVkGpu.cpp
+++ b/src/gpu/vk/GrVkGpu.cpp
@@ -1359,11 +1359,7 @@ GrBackendTexture GrVkGpu::createTestingOnlyBackendTexture(const void* srcData, i
                                         &info)) {
         return {};
     }
-    GrBackendTexture beTex = GrBackendTexture(w, h, info);
-    // Lots of tests don't go through Skia's public interface which will set the config so for
-    // testing we make sure we set a config here.
-    beTex.setPixelConfig(config);
-    return beTex;
+    return GrBackendTexture(w, h, info);
 }
 
 bool GrVkGpu::isTestingOnlyBackendTexture(const GrBackendTexture& tex) const {
@@ -1413,11 +1409,7 @@ GrBackendRenderTarget GrVkGpu::createTestingOnlyBackendRenderTarget(int w, int h
                                         &info)) {
         return {};
     }
-    GrBackendRenderTarget beRT = GrBackendRenderTarget(w, h, 1, 0, info);
-    // Lots of tests don't go through Skia's public interface which will set the config so for
-    // testing we make sure we set a config here.
-    beRT.setPixelConfig(config);
-    return beRT;
+    return {w, h, 1, 0, info};
 }
 
 void GrVkGpu::deleteTestingOnlyBackendRenderTarget(const GrBackendRenderTarget& rt) {
diff --git a/src/gpu/vk/GrVkUtil.cpp b/src/gpu/vk/GrVkUtil.cpp
index b0aa3d4c14..2b0bba732d 100644
--- a/src/gpu/vk/GrVkUtil.cpp
+++ b/src/gpu/vk/GrVkUtil.cpp
@@ -75,6 +75,40 @@ bool GrPixelConfigToVkFormat(GrPixelConfig config, VkFormat* format) {
     return false;
 }
 
+GrPixelConfig GrVkFormatToPixelConfig(VkFormat format) {
+    switch (format) {
+        case VK_FORMAT_R8G8B8A8_UNORM:
+            return kRGBA_8888_GrPixelConfig;
+        case VK_FORMAT_B8G8R8A8_UNORM:
+            return kBGRA_8888_GrPixelConfig;
+        case VK_FORMAT_R8G8B8A8_SRGB:
+            return kSRGBA_8888_GrPixelConfig;
+        case VK_FORMAT_B8G8R8A8_SRGB:
+            return kSBGRA_8888_GrPixelConfig;
+        case VK_FORMAT_A2B10G10R10_UNORM_PACK32:
+            return kRGBA_1010102_GrPixelConfig;
+        case VK_FORMAT_R5G6B5_UNORM_PACK16:
+            return kRGB_565_GrPixelConfig;
+            break;
+        case VK_FORMAT_B4G4R4A4_UNORM_PACK16:
+            // R4G4B4A4 is not required to be supported so we actually
+            // store RGBA_4444 data as B4G4R4A4.
+            return kRGBA_4444_GrPixelConfig;
+        case VK_FORMAT_R8_UNORM:
+            return kAlpha_8_GrPixelConfig;
+        case VK_FORMAT_R32G32B32A32_SFLOAT:
+            return kRGBA_float_GrPixelConfig;
+        case VK_FORMAT_R32G32_SFLOAT:
+            return kRG_float_GrPixelConfig;
+        case VK_FORMAT_R16G16B16A16_SFLOAT:
+            return kRGBA_half_GrPixelConfig;
+        case VK_FORMAT_R16_SFLOAT:
+            return kAlpha_half_GrPixelConfig;
+        default:
+            return kUnknown_GrPixelConfig;
+    }
+}
+
 bool GrVkFormatPixelConfigPairIsValid(VkFormat format, GrPixelConfig config) {
     switch (format) {
         case VK_FORMAT_R8G8B8A8_UNORM:
diff --git a/src/gpu/vk/GrVkUtil.h b/src/gpu/vk/GrVkUtil.h
index 7c56c6941f..71cc5d4e6a 100644
--- a/src/gpu/vk/GrVkUtil.h
+++ b/src/gpu/vk/GrVkUtil.h
@@ -33,6 +33,11 @@ class GrVkGpu;
  */
 bool GrPixelConfigToVkFormat(GrPixelConfig config, VkFormat* format);
 
+/**
+* Returns the GrPixelConfig for the given vulkan texture format
+*/
+GrPixelConfig GrVkFormatToPixelConfig(VkFormat format);
+
 bool GrVkFormatIsSupported(VkFormat);
 
 /**