Prevent GetSymbol() using SymbolKey from being inlined

Function inlining of the GetSymbol function using SymbolKey instance as a key is not negligible because that might bloat out code size especially with the Android compiler.

This CL prevents function inlining of the GetSymbol function by defining it in v8_private_property.cc.

Bug: 715418
Change-Id: I73aa068ee71802ed4b0ebf001d846520ae13be08
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1880900Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Commit-Queue: Marina Sakai <marinasakai@google.com>
Cr-Commit-Position: refs/heads/master@{#709856}

third_party/blink/renderer/platform/bindings/v8_private_property.cc

@@ -18,6 +18,23 @@ v8::MaybeLocal<v8::Value> V8PrivateProperty::Symbol::GetFromMainWorld(
                            : GetOrUndefined(wrapper);
 }
 
+V8PrivateProperty::Symbol V8PrivateProperty::GetSymbol(
+    v8::Isolate* isolate,
+    const V8PrivateProperty::SymbolKey& key) {
+  V8PrivateProperty* private_prop =
+      V8PerIsolateData::From(isolate)->PrivateProperty();
+  auto& symbol_map = private_prop->symbol_map_;
+  auto iter = symbol_map.find(&key);
+  v8::Local<v8::Private> v8_private;
+  if (UNLIKELY(iter == symbol_map.end())) {
+    v8_private = CreateV8Private(isolate, key.GetDescription());
+    symbol_map.insert(&key, v8::Eternal<v8::Private>(isolate, v8_private));
+  } else {
+    v8_private = iter->value.Get(isolate);
+  }
+  return Symbol(isolate, v8_private);
+}
+
 v8::Local<v8::Private> V8PrivateProperty::CreateV8Private(v8::Isolate* isolate,
                                                           const char* symbol) {
   return v8::Private::New(isolate, V8String(isolate, symbol));

third_party/blink/renderer/platform/bindings/v8_private_property.h

@@ -135,7 +135,7 @@ class PLATFORM_EXPORT V8PrivateProperty {
   //
   // We can improve ability of tracking private properties by using an instance
   // of this class. |desc_| is a description of the private property.
-  class PLATFORM_EXPORT SymbolKey {
+  class PLATFORM_EXPORT SymbolKey final {
    public:
     // Note that, unlike a string class, the lifetime of |desc| must be longer
     // than this SymbolKey, i.e. this SymbolKey does not copy |desc| nor have
@@ -220,20 +220,7 @@ class PLATFORM_EXPORT V8PrivateProperty {
 
   // Returns a Symbol to access a private property. Symbol instances from same
   // |key| are guaranteed to access the same property.
-  static Symbol GetSymbol(v8::Isolate* isolate, const SymbolKey& key) {
-    V8PrivateProperty* private_prop =
-        V8PerIsolateData::From(isolate)->PrivateProperty();
-    auto& symbol_map = private_prop->symbol_map_;
-    auto iter = symbol_map.find(&key);
-    v8::Local<v8::Private> v8_private;
-    if (UNLIKELY(iter == symbol_map.end())) {
-      v8_private = CreateV8Private(isolate, key.GetDescription());
-      symbol_map.insert(&key, v8::Eternal<v8::Private>(isolate, v8_private));
-    } else {
-      v8_private = iter->value.Get(isolate);
-    }
-    return Symbol(isolate, v8_private);
-  }
+  static Symbol GetSymbol(v8::Isolate* isolate, const SymbolKey& key);
 
   // This function is always called after NOTREACHED(). The Symbol returned from
   // this function must not be used.