[WebAssembly] Add blink::feature kWasmCodeCache.

- Adds kWasmCodeCache to blink::features.
- Checks if enabled before creating the cache in the browser.
- Checks if enabled before fetching from cache in renderer.

This is patterned after the Javascript IsolatedCodeCache feature.

Bug: chromium:719172
Change-Id: I1ffea5d8029b2b550c45e3ba25821889c7c2183c
Reviewed-on: https://chromium-review.googlesource.com/c/1341071
Commit-Queue: Bill Budge <bbudge@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609705}

content/browser/code_cache/generated_code_cache_context.cc

@@ -7,6 +7,7 @@
 #include "content/browser/code_cache/generated_code_cache.h"
 #include "content/public/browser/browser_task_traits.h"
 #include "content/public/browser/browser_thread.h"
+#include "third_party/blink/public/common/features.h"
 
 namespace content {
 
@@ -29,9 +30,13 @@ void GeneratedCodeCacheContext::InitializeOnIO(const base::FilePath& path,
   generated_js_code_cache_.reset(
       new GeneratedCodeCache(path.AppendASCII("js"), max_bytes,
                              GeneratedCodeCache::CodeCacheType::kJavaScript));
-  generated_wasm_code_cache_.reset(
-      new GeneratedCodeCache(path.AppendASCII("wasm"), max_bytes,
-                             GeneratedCodeCache::CodeCacheType::kWebAssembly));
+
+  // Only create the Wasm cache if it's enabled.
+  if (base::FeatureList::IsEnabled(blink::features::kWasmCodeCache)) {
+    generated_wasm_code_cache_.reset(new GeneratedCodeCache(
+        path.AppendASCII("wasm"), max_bytes,
+        GeneratedCodeCache::CodeCacheType::kWebAssembly));
+  }
 }
 
 GeneratedCodeCache* GeneratedCodeCacheContext::generated_js_code_cache() const {

content/browser/storage_partition_impl_unittest.cc

@@ -42,6 +42,7 @@
 #include "storage/browser/test/mock_quota_manager.h"
 #include "storage/browser/test/mock_special_storage_policy.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/blink/public/common/features.h"
 
 #if BUILDFLAG(ENABLE_PLUGINS)
 #include "ppapi/shared_impl/ppapi_constants.h"  // nogncheck
@@ -1305,16 +1306,10 @@ TEST_F(StoragePartitionImplTest, ClearCodeCache) {
 
   GURL origin = GURL(kTestOrigin1);
   std::string data("SomeData");
-  std::string data2("SomeData.wasm");
   tester.AddEntry(RemoveCodeCacheTester::kJs, kResourceURL, origin, data);
-  tester.AddEntry(RemoveCodeCacheTester::kWebAssembly, kResourceURL, origin,
-                  data2);
   EXPECT_TRUE(
       tester.ContainsEntry(RemoveCodeCacheTester::kJs, kResourceURL, origin));
   EXPECT_EQ(tester.received_data(), data);
-  EXPECT_TRUE(tester.ContainsEntry(RemoveCodeCacheTester::kWebAssembly,
-                                   kResourceURL, origin));
-  EXPECT_EQ(tester.received_data(), data2);
 
   base::RunLoop run_loop;
   base::ThreadTaskRunnerHandle::Get()->PostTask(
@@ -1323,6 +1318,42 @@ TEST_F(StoragePartitionImplTest, ClearCodeCache) {
 
   EXPECT_FALSE(
       tester.ContainsEntry(RemoveCodeCacheTester::kJs, kResourceURL, origin));
+
+  // Make sure there isn't a second invalid callback sitting in the queue.
+  // (this used to be a bug).
+  base::RunLoop().RunUntilIdle();
+}
+
+TEST_F(StoragePartitionImplTest, ClearWasmCodeCache) {
+  base::test::ScopedFeatureList feature_list;
+  feature_list.InitWithFeatures(
+      std::vector<base::Feature>(
+          {net::features::kIsolatedCodeCache, blink::features::kWasmCodeCache}),
+      std::vector<base::Feature>());
+  ASSERT_TRUE(base::FeatureList::IsEnabled(net::features::kIsolatedCodeCache));
+  ASSERT_TRUE(base::FeatureList::IsEnabled(blink::features::kWasmCodeCache));
+
+  StoragePartitionImpl* partition = static_cast<StoragePartitionImpl*>(
+      BrowserContext::GetDefaultStoragePartition(browser_context()));
+  // Ensure code cache is initialized.
+  base::RunLoop().RunUntilIdle();
+  EXPECT_TRUE(partition->GetGeneratedCodeCacheContext() != nullptr);
+
+  RemoveCodeCacheTester tester(partition->GetGeneratedCodeCacheContext());
+
+  GURL origin = GURL(kTestOrigin1);
+  std::string data("SomeData.wasm");
+  tester.AddEntry(RemoveCodeCacheTester::kWebAssembly, kResourceURL, origin,
+                  data);
+  EXPECT_TRUE(tester.ContainsEntry(RemoveCodeCacheTester::kWebAssembly,
+                                   kResourceURL, origin));
+  EXPECT_EQ(tester.received_data(), data);
+
+  base::RunLoop run_loop;
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::BindOnce(&ClearCodeCache, partition, &run_loop));
+  run_loop.Run();
+
   EXPECT_FALSE(tester.ContainsEntry(RemoveCodeCacheTester::kWebAssembly,
                                     kResourceURL, origin));
 

content/child/runtime_features.cc

@@ -436,6 +436,8 @@ void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
 
   WebRuntimeFeatures::EnableIsolatedCodeCache(
       base::FeatureList::IsEnabled(net::features::kIsolatedCodeCache));
+  WebRuntimeFeatures::EnableWasmCodeCache(
+      base::FeatureList::IsEnabled(blink::features::kWasmCodeCache));
 
   if (base::FeatureList::IsEnabled(features::kSignedHTTPExchange)) {
     WebRuntimeFeatures::EnableSignedHTTPExchange(true);

third_party/blink/common/features.cc

@@ -107,6 +107,12 @@ const base::Feature kJankTracking{"JankTracking",
 const base::Feature kRTCUnifiedPlanByDefault{"RTCUnifiedPlanByDefault",
                                              base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Enables the site isolated Wasm code cache that is keyed on the resource URL
+// and the origin lock of the renderer that is requesting the resource. When
+// this flag is enabled, content/GeneratedCodeCache handles code cache requests.
+const base::Feature kWasmCodeCache = {"WasmCodeCache",
+                                      base::FEATURE_DISABLED_BY_DEFAULT};
+
 const char kAutofillPreviewStyleExperimentBgColorParameterName[] = "bg_color";
 
 const char kAutofillPreviewStyleExperimentColorParameterName[] = "color";

third_party/blink/public/common/features.h

@@ -34,6 +34,7 @@ BLINK_COMMON_EXPORT extern const base::Feature kWritableFilesAPI;
 BLINK_COMMON_EXPORT extern const base::Feature kMixedContentAutoupgrade;
 BLINK_COMMON_EXPORT extern const base::Feature kJankTracking;
 BLINK_COMMON_EXPORT extern const base::Feature kRTCUnifiedPlanByDefault;
+BLINK_COMMON_EXPORT extern const base::Feature kWasmCodeCache;
 
 BLINK_COMMON_EXPORT extern const char
     kAutofillPreviewStyleExperimentBgColorParameterName[];

third_party/blink/public/platform/web_runtime_features.h

@@ -91,6 +91,7 @@ class WebRuntimeFeatures {
   BLINK_PLATFORM_EXPORT static void EnableBloatedRendererDetection(bool);
   BLINK_PLATFORM_EXPORT static void EnableCacheInlineScriptCode(bool);
   BLINK_PLATFORM_EXPORT static void EnableIsolatedCodeCache(bool);
+  BLINK_PLATFORM_EXPORT static void EnableWasmCodeCache(bool);
   BLINK_PLATFORM_EXPORT static void EnableCanvas2dImageChromium(bool);
   BLINK_PLATFORM_EXPORT static void EnableCSSHexAlphaColor(bool);
   BLINK_PLATFORM_EXPORT static void EnableCSSFragmentIdentifiers(bool);

third_party/blink/renderer/platform/exported/web_runtime_features.cc

@@ -116,6 +116,10 @@ void WebRuntimeFeatures::EnableIsolatedCodeCache(bool enable) {
   RuntimeEnabledFeatures::SetIsolatedCodeCacheEnabled(enable);
 }
 
+void WebRuntimeFeatures::EnableWasmCodeCache(bool enable) {
+  RuntimeEnabledFeatures::SetWasmCodeCacheEnabled(enable);
+}
+
 void WebRuntimeFeatures::EnableCanvas2dImageChromium(bool enable) {
   RuntimeEnabledFeatures::SetCanvas2dImageChromiumEnabled(enable);
 }

third_party/blink/renderer/platform/loader/fetch/resource_loader.cc

@@ -327,6 +327,9 @@ void ResourceLoader::Trace(blink::Visitor* visitor) {
 bool ResourceLoader::ShouldFetchCodeCache() {
   if (!RuntimeEnabledFeatures::IsolatedCodeCacheEnabled())
     return false;
+  if (resource_->GetType() == ResourceType::kRaw &&
+      !RuntimeEnabledFeatures::WasmCodeCacheEnabled())
+    return false;
 
   // TODO(crbug.com/867347): Enable fetching of code caches on non-main threads
   // once code cache has its own mojo interface. Currently it is using

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -1278,6 +1278,10 @@
       name: "WakeLockNavigator",
       status: "experimental",
     },
+    {
+      name: "WasmCodeCache",
+      status: "experimental",
+    },
     {
       name: "WebAnimationsAPI",
       status: "experimental",