Revert "[WASM] Reserve a large block of address space on 32 bit Windo…

…ws."

This reverts commit 2a78cf9.

Reason for revert: This CL breaks Android builds
https://build.chromium.org/p/chromium.android/builders/Android%20Cronet%20Builder%20%28dbg%29/builds/5740
https://build.chromium.org/p/chromium.android/builders/Android%20Cronet%20Marshmallow%2064bit%20Perf/builds/10177
https://build.chromium.org/p/chromium.android/builders/Android%20Cronet%20ARMv6%20Builder/builds/5532


Original change's description:
> [WASM] Reserve a large block of address space on 32 bit Windows.
> 
> - Reserves address space on 32 bit Windows, using
>   base::ReserveAddressSpace. This will be released on the first
>   failure in AllocPages.
> - Implements v8::Platform::OnCriticalMemoryPressure in gin, so V8 alloc
>   failures can also invoke base::ReleaseReservation.
> 
> Bug: chromium:634547
> Change-Id: I9bf7b4bb406bbd138c96ed5091b5900fd8137947
> Reviewed-on: https://chromium-review.googlesource.com/616340
> Reviewed-by: Jeremy Roman <jbroman@chromium.org>
> Reviewed-by: Kentaro Hara <haraken@chromium.org>
> Reviewed-by: Daniel Cheng <dcheng@chromium.org>
> Reviewed-by: Chris Palmer <palmer@chromium.org>
> Reviewed-by: Brad Nelson <bradnelson@chromium.org>
> Commit-Queue: Bill Budge <bbudge@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#495411}

TBR=bradnelson@chromium.org,palmer@chromium.org,dcheng@chromium.org,bbudge@chromium.org,jschuh@chromium.org,jbroman@chromium.org,haraken@chromium.org,slangley@chromium.org

Change-Id: I5acb08fb0caa798061bd9e24209794a45925b8fc
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:634547
Reviewed-on: https://chromium-review.googlesource.com/620346
Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Commit-Queue: Hitoshi Yoshida <peria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#495430}

gin/public/v8_platform.h

@@ -19,7 +19,6 @@ class GIN_EXPORT V8Platform : public v8::Platform {
   static V8Platform* Get();
 
   // v8::Platform implementation.
-  void OnCriticalMemoryPressure() override;
   size_t NumberOfAvailableBackgroundThreads() override;
   void CallOnBackgroundThread(
       v8::Task* task,

gin/v8_platform.cc

@@ -6,7 +6,6 @@
 
 #include <algorithm>
 
-#include "base/allocator/partition_allocator/page_allocator.h"
 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/location.h"
@@ -196,10 +195,6 @@ V8Platform::V8Platform() : tracing_controller_(new TracingControllerImpl) {}
 
 V8Platform::~V8Platform() {}
 
-void V8Platform::OnCriticalMemoryPressure() {
-  base::ReleaseReservation();
-}
-
 size_t V8Platform::NumberOfAvailableBackgroundThreads() {
   return std::max(1, base::TaskScheduler::GetInstance()
                          ->GetMaxConcurrentTasksWithTraitsDeprecated(

third_party/WebKit/Source/controller/BlinkInitializer.cpp

@@ -29,7 +29,6 @@
  */
 
 #include "bindings/core/v8/V8Initializer.h"
-#include "build/build_config.h"
 #include "core/animation/AnimationClock.h"
 #include "modules/ModulesInitializer.h"
 #include "platform/bindings/Microtask.h"
@@ -69,25 +68,6 @@ static ModulesInitializer& GetModulesInitializer() {
 void Initialize(Platform* platform) {
   Platform::Initialize(platform);
 
-#if !defined(ARCH_CPU_X86_64) && !defined(ARCH_CPU_ARM64) && defined(OS_WIN)
-  // Reserve address space on 32 bit Windows, to make it likelier that large
-  // array buffer allocations succeed.
-  BOOL is_wow_64 = -1;
-  if (!IsWow64Process(GetCurrentProcess(), &is_wow_64))
-    is_wow_64 = FALSE;
-  if (!is_wow_64) {
-    // Try to reserve as much address space as we reasonably can.
-    const size_t kMB = 1024 * 1024;
-    for (size_t size = 512 * kMB; size >= 32 * kMB; size -= 16 * kMB) {
-      const size_t kAlignment = 64 << 10;  // 64K (wasm page size)
-      if (base::ReserveAddressSpace(size, kAlignment)) {
-        break;
-      }
-    }
-  }
-#endif  // !defined(ARCH_CPU_X86_64) && !defined(ARCH_CPU_ARM64) &&
-        // defined(OS_WIN)
-
   V8Initializer::InitializeMainThread();
 
   GetModulesInitializer().Initialize();