Remove MemoryCoordinatorClient from content/gpu.

BUG=888904

Change-Id: I5e8b2d3d3e2d0975cc5713fdae4b85969308a906
Reviewed-on: https://chromium-review.googlesource.com/c/1264435Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Takashi Sakamoto <tasak@google.com>
Cr-Commit-Position: refs/heads/master@{#599582}

content/gpu/gpu_child_thread.cc

@@ -11,7 +11,6 @@
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
-#include "base/memory/memory_coordinator_client_registry.h"
 #include "base/memory/weak_ptr.h"
 #include "base/run_loop.h"
 #include "base/sequenced_task_runner.h"
@@ -193,7 +192,6 @@ GpuChildThread::GpuChildThread(base::RepeatingClosure quit_closure,
 }
 
 GpuChildThread::~GpuChildThread() {
-  base::MemoryCoordinatorClientRegistry::GetInstance()->Unregister(this);
 }
 
 void GpuChildThread::Init(const base::Time& process_start_time) {
@@ -230,7 +228,6 @@ void GpuChildThread::Init(const base::Time& process_start_time) {
 
   StartServiceManagerConnection();
 
-  base::MemoryCoordinatorClientRegistry::GetInstance()->Register(this);
   memory_pressure_listener_ =
       std::make_unique<base::MemoryPressureListener>(base::BindRepeating(
           &GpuChildThread::OnMemoryPressure, base::Unretained(this)));
@@ -308,17 +305,11 @@ void GpuChildThread::BindServiceFactoryRequest(
                                        std::move(request));
 }
 
-void GpuChildThread::OnTrimMemoryImmediately() {
-  OnPurgeMemory();
-}
-
 void GpuChildThread::OnMemoryPressure(
     base::MemoryPressureListener::MemoryPressureLevel level) {
-  if (level == base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL)
-    OnPurgeMemory();
-}
+  if (level != base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL)
+    return;
 
-void GpuChildThread::OnPurgeMemory() {
   base::allocator::ReleaseFreeMemory();
   if (viz_main_.discardable_shared_memory_manager())
     viz_main_.discardable_shared_memory_manager()->ReleaseFreeMemory();

content/gpu/gpu_child_thread.h

@@ -14,7 +14,6 @@
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/macros.h"
-#include "base/memory/memory_coordinator_client.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
@@ -47,8 +46,7 @@ class GpuServiceFactory;
 // IPC messages to gpu::GpuChannelManager, which is responsible for issuing
 // rendering commands to the GPU.
 class GpuChildThread : public ChildThreadImpl,
-                       public viz::VizMainImpl::Delegate,
-                       public base::MemoryCoordinatorClient {
+                       public viz::VizMainImpl::Delegate {
  public:
   GpuChildThread(base::RepeatingClosure quit_closure,
                  std::unique_ptr<gpu::GpuInit> gpu_init,
@@ -85,10 +83,6 @@ class GpuChildThread : public ChildThreadImpl,
       base::SingleThreadTaskRunner* task_runner) override;
   void QuitMainMessageLoop() override;
 
-  // ChildMemoryCoordinatorDelegate implementation.
-  void OnTrimMemoryImmediately() override;
-  // base::MemoryCoordinatorClient implementation:
-  void OnPurgeMemory() override;
   void OnMemoryPressure(
       base::MemoryPressureListener::MemoryPressureLevel level);