Revert of discardable_memory: Using mojo IPC to replace Chrome IPC

content/renderer/render_thread_impl.h

Index: content/renderer/render_thread_impl.h
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 0d9d4281632b7d0a4d84719f0abbf32d57135391..ea344d4d16d53c0aa8f1eedb75c49adf333fedcd 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -76,10 +76,6 @@
 class TaskGraphRunner;
 }
 
-namespace discardable_memory {
-class ClientDiscardableSharedMemoryManager;
-}
-
 namespace gpu {
 class GpuChannelHost;
 }
@@ -271,11 +267,6 @@
     layout_test_deps_ = std::move(deps);
   }
 
-  discardable_memory::ClientDiscardableSharedMemoryManager*
-  GetDiscardableSharedMemoryManagerForTest() {
-    return discardable_shared_memory_manager_.get();
-  }
-
   RendererBlinkPlatformImpl* blink_platform_impl() const {
     DCHECK(blink_platform_impl_);
     return blink_platform_impl_.get();
@@ -563,9 +554,6 @@
 
   void OnRendererInterfaceRequest(mojom::RendererAssociatedRequest request);
 
-  std::unique_ptr<discardable_memory::ClientDiscardableSharedMemoryManager>
-      discardable_shared_memory_manager_;
-
   // These objects live solely on the render thread.
   std::unique_ptr<AppCacheDispatcher> appcache_dispatcher_;
   std::unique_ptr<DomStorageDispatcher> dom_storage_dispatcher_;