Set preferredStorageMode in capabilities so we don't duplicate the logic in multiple places

Author: dgovil

pxr/imaging/hgiMetal/blitCmds.mm

@@ -203,11 +203,7 @@
 
     mtlDesc.mipmapLevelCount = dstTexDesc.mipLevels;
     mtlDesc.arrayLength = dstTexDesc.layerCount;
-#if defined(ARCH_OS_OSX)
-    mtlDesc.resourceOptions = MTLResourceStorageModeManaged;
-#else
-    mtlDesc.resourceOptions = MTLResourceStorageModeShared;
-#endif
+    mtlDesc.resourceOptions = _hgi->GetCapabilities()->preferredStorageMode;
     mtlDesc.sampleCount = 1;
     if (dstTexDesc.type == HgiTextureType3D) {
         mtlDesc.depth = depth;

pxr/imaging/hgiMetal/capabilities.h

@@ -32,6 +32,7 @@ class HgiMetalCapabilities final : public HgiCapabilities
     int GetShaderVersion() const override;
 
     MTLResourceOptions defaultStorageMode;
+    MTLResourceOptions preferredStorageMode;
     bool hasVertexMemoryBarrier;
     bool useParallelEncoder;
     bool requiresIndirectDrawFix;

pxr/imaging/hgiMetal/capabilities.mm

@@ -26,7 +26,13 @@
     bool hasIntelGPU = false;
 #if defined(ARCH_OS_OSX)
     hasIntelGPU = [device isLowPower];
+    if (![device hasUnifiedMemory]) {
+        preferredStorageMode = MTLResourceStorageModeManaged;
+    } else
 #endif
+    {
+        preferredStorageMode = MTLResourceStorageModeShared;
+    }
     defaultStorageMode = MTLResourceStorageModeShared;
     bool unifiedMemory = false;
     bool barycentrics = false;

pxr/imaging/hgiMetal/texture.mm

@@ -24,15 +24,7 @@
     MTLTextureUsage usage = MTLTextureUsageShaderRead;
 
     if (desc.initialData && desc.pixelsByteSize > 0) {
-        #if defined(ARCH_OS_OSX)
-        id<MTLDevice> device = hgi->GetPrimaryDevice();
-        if (![device hasUnifiedMemory]) {
-            resourceOptions = MTLResourceStorageModeManaged;
-        } else
-        #endif
-        {
-            resourceOptions = MTLResourceStorageModeShared;
-        }
+        resourceOptions = hgi->GetCapabilities()->preferredStorageMode;
     }
 
     MTLPixelFormat mtlFormat = HgiMetalConversions::GetPixelFormat(