[v8] Remove overrides for deprecated methods

The methods are deprecated and will be removed in V8 v8.1, thus we need
to stop overriding them in chromium.

R=rmcilroy@chromium.org
CC=ulan@chromium.org

Bug: v8:9810
Change-Id: I43d47c87c388a7c93ea87956b75f1db79d78fdb2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1871592Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708150}

gin/public/v8_platform.h

@@ -34,12 +34,6 @@ class GIN_EXPORT V8Platform : public v8::Platform {
       std::unique_ptr<v8::Task> task) override;
   void CallDelayedOnWorkerThread(std::unique_ptr<v8::Task> task,
                                  double delay_in_seconds) override;
-  void CallOnForegroundThread(v8::Isolate* isolate, v8::Task* task) override;
-  void CallDelayedOnForegroundThread(v8::Isolate* isolate,
-                                     v8::Task* task,
-                                     double delay_in_seconds) override;
-  void CallIdleOnForegroundThread(v8::Isolate* isolate,
-                                  v8::IdleTask* task) override;
   bool IdleTasksEnabled(v8::Isolate* isolate) override;
   double MonotonicallyIncreasingTime() override;
   double CurrentClockTimeMillis() override;

gin/v8_platform.cc

@@ -440,25 +440,6 @@ void V8Platform::CallDelayedOnWorkerThread(std::unique_ptr<v8::Task> task,
                         base::TimeDelta::FromSecondsD(delay_in_seconds));
 }
 
-void V8Platform::CallOnForegroundThread(v8::Isolate* isolate, v8::Task* task) {
-  PerIsolateData* data = PerIsolateData::From(isolate);
-  data->task_runner()->PostTask(std::unique_ptr<v8::Task>(task));
-}
-
-void V8Platform::CallDelayedOnForegroundThread(v8::Isolate* isolate,
-                                               v8::Task* task,
-                                               double delay_in_seconds) {
-  PerIsolateData* data = PerIsolateData::From(isolate);
-  data->task_runner()->PostDelayedTask(std::unique_ptr<v8::Task>(task),
-                                       delay_in_seconds);
-}
-
-void V8Platform::CallIdleOnForegroundThread(v8::Isolate* isolate,
-                                            v8::IdleTask* task) {
-  PerIsolateData* data = PerIsolateData::From(isolate);
-  data->task_runner()->PostIdleTask(std::unique_ptr<v8::IdleTask>(task));
-}
-
 bool V8Platform::IdleTasksEnabled(v8::Isolate* isolate) {
   return PerIsolateData::From(isolate)->task_runner()->IdleTasksEnabled();
 }