fix: correct redefinition which is invalid C++ (#36096)

* fix: correct redefinition which is invalid C++

See https://stackoverflow.com/a/15538759 for an explanation of class scope.
GCC gives an error when compiling this code: https://godbolt.org/z/sYhc3cMjE

* Update export_gin_v8platform_pageallocator_for_usage_outside_of_the_gin.patch

---------

Co-authored-by: Cheng Zhao <[email protected]>
Co-authored-by: Cheng Zhao <[email protected]>

patches/chromium/export_gin_v8platform_pageallocator_for_usage_outside_of_the_gin.patch

@@ -9,26 +9,26 @@ correctly tagged with MAP_JIT we need to use gins page allocator instead
 of the default V8 allocator.  This probably can't be usptreamed.
 
 diff --git a/gin/public/v8_platform.h b/gin/public/v8_platform.h
-index c4f2df96133012faebec25ac3a738c34cd6b4cf8..1b0333b2efe05a659e161f28ce6c01e572fddcef 100644
+index c4f2df96133012faebec25ac3a738c34cd6b4cf8..54bc2625686b9344c2c793c74589ed85de8227ba 100644
 --- a/gin/public/v8_platform.h
 +++ b/gin/public/v8_platform.h
 @@ -30,6 +30,7 @@ class GIN_EXPORT V8Platform : public v8::Platform {
    // enabling Arm's Branch Target Instructions for executable pages. This is
    // verified in the tests for gin::PageAllocator.
    PageAllocator* GetPageAllocator() override;
-+  static PageAllocator* PageAllocator();
++  static PageAllocator* GetCurrentPageAllocator();
    void OnCriticalMemoryPressure() override;
    v8::ZoneBackingAllocator* GetZoneBackingAllocator() override;
  #endif
 diff --git a/gin/v8_platform.cc b/gin/v8_platform.cc
-index bbb16efbf5208989fa88c7f6d83d36aa5e54a0d1..1ead276abf4327d48a816d8b520ebe958b5aa17b 100644
+index bbb16efbf5208989fa88c7f6d83d36aa5e54a0d1..ef562c9a9abed85198282728287637d178a0af0f 100644
 --- a/gin/v8_platform.cc
 +++ b/gin/v8_platform.cc
 @@ -370,6 +370,10 @@ PageAllocator* V8Platform::GetPageAllocator() {
    return g_page_allocator.Pointer();
  }
  
-+PageAllocator* V8Platform::PageAllocator() {
++PageAllocator* V8Platform::GetCurrentPageAllocator() {
 +  return g_page_allocator.Pointer();
 +}
 +

shell/browser/javascript_environment.cc

@@ -267,7 +267,7 @@ v8::Isolate* JavascriptEnvironment::Initialize(uv_loop_t* event_loop,
   node::tracing::TraceEventHelper::SetAgent(tracing_agent);
   platform_ = node::MultiIsolatePlatform::Create(
       base::RecommendedMaxNumberOfThreadsInThreadGroup(3, 8, 0.1, 0),
-      tracing_controller, gin::V8Platform::PageAllocator());
+      tracing_controller, gin::V8Platform::GetCurrentPageAllocator());
 
   v8::V8::InitializePlatform(platform_.get());
   gin::IsolateHolder::Initialize(gin::IsolateHolder::kNonStrictMode,