Use MemoryCoordinatorClientRegistry in BlinkPlatformImpl::requestPurgeMemory()

content/renderer/renderer_blink_platform_impl.h

Index: content/renderer/renderer_blink_platform_impl.h
diff --git a/content/renderer/renderer_blink_platform_impl.h b/content/renderer/renderer_blink_platform_impl.h
index 666713c5327543d6210d3e1615b6e41a9fb475a8..df62a9920d1fd33bb5bd6d3f957c8e6566cebe07 100644
--- a/content/renderer/renderer_blink_platform_impl.h
+++ b/content/renderer/renderer_blink_platform_impl.h
@@ -50,7 +50,6 @@ class InterfaceProvider;
 
 namespace content {
 class BlinkInterfaceProviderImpl;
-class ChildMemoryCoordinatorImpl;
 class LocalStorageCachedAreas;
 class PlatformEventObserverBase;
 class QuotaMessageFilter;
@@ -63,8 +62,7 @@ class CONTENT_EXPORT RendererBlinkPlatformImpl : public BlinkPlatformImpl {
  public:
   RendererBlinkPlatformImpl(
       blink::scheduler::RendererScheduler* renderer_scheduler,
-      base::WeakPtr<service_manager::InterfaceProvider> remote_interfaces,
-      ChildMemoryCoordinatorImpl* memory_coordinator);
+      base::WeakPtr<service_manager::InterfaceProvider> remote_interfaces);
   ~RendererBlinkPlatformImpl() override;
 
   // Shutdown must be called just prior to shutting down blink.
@@ -301,8 +299,6 @@ class CONTENT_EXPORT RendererBlinkPlatformImpl : public BlinkPlatformImpl {
 
   mojom::URLLoaderFactoryAssociatedPtr url_loader_factory_;
 
-  ChildMemoryCoordinatorImpl* memory_coordinator_;  // NOT OWNED
-
   DISALLOW_COPY_AND_ASSIGN(RendererBlinkPlatformImpl);
 };