Remove PersistentCache and suppress shader cache tests.

- Removed to allow for easier development changes to caching interface as it is implemented for pipeline caching without having to keep supporting this incomplete feature.

Bug: dawn:549, dawn:1341
Change-Id: Id27deca45ac5607a4a6a7a016b19e3d60693ed72
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/87610
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Shrek Shao <shrekshao@google.com>
Commit-Queue: Loko Kung <lokokung@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>

src/dawn/native/Device.cpp

@@ -40,7 +40,6 @@
 #include "dawn/native/Instance.h"
 #include "dawn/native/InternalPipelineStore.h"
 #include "dawn/native/ObjectType_autogen.h"
-#include "dawn/native/PersistentCache.h"
 #include "dawn/native/QuerySet.h"
 #include "dawn/native/Queue.h"
 #include "dawn/native/RenderBundleEncoder.h"
@@ -257,7 +256,6 @@ namespace dawn::native {
         mCallbackTaskManager = std::make_unique<CallbackTaskManager>();
         mDeprecationWarnings = std::make_unique<DeprecationWarnings>();
         mInternalPipelineStore = std::make_unique<InternalPipelineStore>(this);
-        mPersistentCache = std::make_unique<PersistentCache>(this);
 
         ASSERT(GetPlatform() != nullptr);
         mWorkerTaskPool = GetPlatform()->CreateWorkerTaskPool();
@@ -413,7 +411,6 @@ namespace dawn::native {
         mDynamicUploader = nullptr;
         mCallbackTaskManager = nullptr;
         mAsyncTaskManager = nullptr;
-        mPersistentCache = nullptr;
         mEmptyBindGroupLayout = nullptr;
         mInternalPipelineStore = nullptr;
         mExternalTexturePlaceholderView = nullptr;
@@ -574,11 +571,6 @@ namespace dawn::native {
         return returnValue;
     }
 
-    PersistentCache* DeviceBase::GetPersistentCache() {
-        ASSERT(mPersistentCache.get() != nullptr);
-        return mPersistentCache.get();
-    }
-
     BlobCache* DeviceBase::GetBlobCache() {
         return mInstance->GetBlobCache();
     }