Revert 265469 "Fix slow TextureManager::StopTracking()"

This broke mac and asan builders. See following for one:
http://build.chromium.org/p/chromium.memory/builders/Linux%20ASan%20LSan%20Tests%20%281%29/builds/1584/steps/gpu_unittests/logs/AsyncPixelTransfers 

> Fix slow TextureManager::StopTracking()
> 
> Iterating an ObserverList which uses WeakPtr items seems very slow.
> 
> Changing to std::vector<> gives about a 15X speedup.
> Further skipping the observer call backs for TextureRefs with no current observers should cut this close to 0.
> 
> BUG=365536
> 
> Review URL: https://codereview.chromium.org/246353002

TBR=vmiura@chromium.org

Review URL: https://codereview.chromium.org/247343003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@265542 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 13 insertions, 53 deletions

diff --git a/gpu/command_buffer/service/async_pixel_transfer_manager.cc b/gpu/command_buffer/service/async_pixel_transfer_manager.cc
index efc893a..3084dd6 100644
--- a/gpu/command_buffer/service/async_pixel_transfer_manager.cc
+++ b/gpu/command_buffer/service/async_pixel_transfer_manager.cc
@@ -17,12 +17,6 @@ AsyncPixelTransferManager::AsyncPixelTransferManager() {}
 AsyncPixelTransferManager::~AsyncPixelTransferManager() {
   if (manager_)
     manager_->RemoveObserver(this);
-
-  for (TextureToDelegateMap::iterator ref = delegate_map_.begin();
-       ref != delegate_map_.end();
-       ref++) {
-    ref->first->RemoveObserver();
-  }
 }
 
 void AsyncPixelTransferManager::Initialize(gles2::TextureManager* manager) {
@@ -38,7 +32,6 @@ AsyncPixelTransferManager::CreatePixelTransferDelegate(
   AsyncPixelTransferDelegate* delegate =
       CreatePixelTransferDelegateImpl(ref, define_params);
   delegate_map_[ref] = make_linked_ptr(delegate);
-  ref->AddObserver();
   return delegate;
 }
 
@@ -56,10 +49,8 @@ AsyncPixelTransferManager::GetPixelTransferDelegate(
 void AsyncPixelTransferManager::ClearPixelTransferDelegateForTest(
     gles2::TextureRef* ref) {
   TextureToDelegateMap::iterator it = delegate_map_.find(ref);
-  if (it != delegate_map_.end()) {
+  if (it != delegate_map_.end())
     delegate_map_.erase(it);
-    ref->RemoveObserver();
-  }
 }
 
 bool AsyncPixelTransferManager::AsyncTransferIsInProgress(
@@ -78,10 +69,8 @@ void AsyncPixelTransferManager::OnTextureManagerDestroying(
 void AsyncPixelTransferManager::OnTextureRefDestroying(
     gles2::TextureRef* texture) {
   TextureToDelegateMap::iterator it = delegate_map_.find(texture);
-  if (it != delegate_map_.end()) {
+  if (it != delegate_map_.end())
     delegate_map_.erase(it);
-    texture->RemoveObserver();
-  }
 }
 
 }  // namespace gpu
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_unittest.cc b/gpu/command_buffer/service/gles2_cmd_decoder_unittest.cc
index 9f2518a..8691dd1 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_unittest.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_unittest.cc
@@ -8389,7 +8389,6 @@ TEST_F(GLES2DecoderManualInitTest, AsyncPixelTransfers) {
   // AsyncTexImage2D
   {
     // Create transfer state since it doesn't exist.
-    EXPECT_EQ(texture_ref->num_observers(), 0);
     EXPECT_CALL(*manager, CreatePixelTransferDelegateImpl(texture_ref, _))
         .WillOnce(Return(
             delegate = new StrictMock<gpu::MockAsyncPixelTransferDelegate>))
@@ -8409,7 +8408,6 @@ TEST_F(GLES2DecoderManualInitTest, AsyncPixelTransfers) {
     EXPECT_TRUE(texture->SafeToRenderFrom());
     GLsizei width, height;
     EXPECT_FALSE(texture->GetLevelSize(GL_TEXTURE_2D, 0, &width, &height));
-    EXPECT_EQ(texture_ref->num_observers(), 1);
   }
   {
     // Async redefinitions are not allowed!
@@ -8443,10 +8441,8 @@ TEST_F(GLES2DecoderManualInitTest, AsyncPixelTransfers) {
   }
 
   // AsyncTexSubImage2D
-  EXPECT_CALL(*delegate, Destroy()).RetiresOnSaturation();
   decoder_->GetAsyncPixelTransferManager()
       ->ClearPixelTransferDelegateForTest(texture_ref);
-  EXPECT_EQ(texture_ref->num_observers(), 0);
   texture->SetImmutable(false);
   {
     // Create transfer state since it doesn't exist.
@@ -8502,13 +8498,11 @@ TEST_F(GLES2DecoderManualInitTest, AsyncPixelTransfers) {
 
   // Delete delegate on DeleteTexture.
   {
-    EXPECT_EQ(texture_ref->num_observers(), 1);
     EXPECT_CALL(*delegate, Destroy()).RetiresOnSaturation();
     DoDeleteTexture(client_texture_id_, kServiceTextureId);
     EXPECT_FALSE(
         decoder_->GetAsyncPixelTransferManager()->GetPixelTransferDelegate(
             texture_ref));
-    EXPECT_EQ(texture_ref->num_observers(), 0);
     texture = NULL;
     texture_ref = NULL;
     delegate = NULL;
@@ -8587,11 +8581,6 @@ TEST_F(GLES2DecoderManualInitTest, AsyncPixelTransfers) {
     EXPECT_EQ(error::kNoError, ExecuteCmd(wait_all_cmd));
     EXPECT_EQ(GL_NO_ERROR, GetGLError());
   }
-
-  // Remove PixelTransferManager before the decoder destroys.
-  EXPECT_CALL(*delegate, Destroy()).RetiresOnSaturation();
-  decoder_->ResetAsyncPixelTransferManagerForTest();
-  manager = NULL;
 }
 
 TEST_F(GLES2DecoderManualInitTest, AsyncPixelTransferManager) {
@@ -8642,14 +8631,11 @@ TEST_F(GLES2DecoderManualInitTest, AsyncPixelTransferManager) {
 
   // Delete delegate on manager teardown.
   {
-    EXPECT_EQ(texture_ref->num_observers(), 1);
     EXPECT_CALL(*delegate, Destroy()).RetiresOnSaturation();
     decoder_->ResetAsyncPixelTransferManagerForTest();
-    manager = NULL;
 
     // Texture ref still valid.
     EXPECT_EQ(texture_ref, GetTexture(client_texture_id_));
-    EXPECT_EQ(texture_ref->num_observers(), 0);
   }
 }
 
diff --git a/gpu/command_buffer/service/texture_manager.cc b/gpu/command_buffer/service/texture_manager.cc
index c3a824c..8f7703b 100644
--- a/gpu/command_buffer/service/texture_manager.cc
+++ b/gpu/command_buffer/service/texture_manager.cc
@@ -66,8 +66,9 @@ TextureManager::DestructionObserver::DestructionObserver() {}
 TextureManager::DestructionObserver::~DestructionObserver() {}
 
 TextureManager::~TextureManager() {
-  for (unsigned int i = 0; i < destruction_observers_.size(); i++)
-    destruction_observers_[i]->OnTextureManagerDestroying(this);
+  FOR_EACH_OBSERVER(DestructionObserver,
+                    destruction_observers_,
+                    OnTextureManagerDestroying(this));
 
   DCHECK(textures_.empty());
 
@@ -872,8 +873,7 @@ TextureRef::TextureRef(TextureManager* manager,
                        Texture* texture)
     : manager_(manager),
       texture_(texture),
-      client_id_(client_id),
-      num_observers_(0) {
+      client_id_(client_id) {
   DCHECK(manager_);
   DCHECK(texture_);
   texture_->AddTextureRef(this);
@@ -1222,12 +1222,9 @@ void TextureManager::StartTracking(TextureRef* ref) {
 }
 
 void TextureManager::StopTracking(TextureRef* ref) {
-  if (ref->num_observers()) {
-    for (unsigned int i = 0; i < destruction_observers_.size(); i++) {
-      destruction_observers_[i]->OnTextureRefDestroying(ref);
-    }
-    DCHECK_EQ(ref->num_observers(), 0);
-  }
+  FOR_EACH_OBSERVER(DestructionObserver,
+                    destruction_observers_,
+                    OnTextureRefDestroying(ref));
 
   Texture* texture = ref->texture();
 
diff --git a/gpu/command_buffer/service/texture_manager.h b/gpu/command_buffer/service/texture_manager.h
index 6b3a32e..8513264 100644
--- a/gpu/command_buffer/service/texture_manager.h
+++ b/gpu/command_buffer/service/texture_manager.h
@@ -13,6 +13,7 @@
 #include "base/containers/hash_tables.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
+#include "base/observer_list.h"
 #include "gpu/command_buffer/service/async_pixel_transfer_delegate.h"
 #include "gpu/command_buffer/service/gl_utils.h"
 #include "gpu/command_buffer/service/memory_tracking.h"
@@ -403,15 +404,10 @@ class GPU_EXPORT TextureRef : public base::RefCounted<TextureRef> {
   static scoped_refptr<TextureRef> Create(TextureManager* manager,
                                           GLuint client_id,
                                           GLuint service_id);
-
-  void AddObserver() { num_observers_++; }
-  void RemoveObserver() { num_observers_--; }
-
   const Texture* texture() const { return texture_; }
   Texture* texture() { return texture_; }
   GLuint client_id() const { return client_id_; }
   GLuint service_id() const { return texture_->service_id(); }
-  GLint num_observers() const { return num_observers_; }
 
  private:
   friend class base::RefCounted<TextureRef>;
@@ -426,7 +422,6 @@ class GPU_EXPORT TextureRef : public base::RefCounted<TextureRef> {
   TextureManager* manager_;
   Texture* texture_;
   GLuint client_id_;
-  GLint num_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(TextureRef);
 };
@@ -687,18 +682,11 @@ class GPU_EXPORT TextureManager {
       std::string* signature) const;
 
   void AddObserver(DestructionObserver* observer) {
-    destruction_observers_.push_back(observer);
+    destruction_observers_.AddObserver(observer);
   }
 
   void RemoveObserver(DestructionObserver* observer) {
-    for (unsigned int i = 0; i < destruction_observers_.size(); i++) {
-      if (destruction_observers_[i] == observer) {
-        std::swap(destruction_observers_[i], destruction_observers_.back());
-        destruction_observers_.pop_back();
-        return;
-      }
-    }
-    NOTREACHED();
+    destruction_observers_.RemoveObserver(observer);
   }
 
   struct DoTextImage2DArguments {
@@ -808,7 +796,7 @@ class GPU_EXPORT TextureManager {
   // The default textures for each target (texture name = 0)
   scoped_refptr<TextureRef> default_textures_[kNumDefaultTextures];
 
-  std::vector<DestructionObserver*> destruction_observers_;
+  ObserverList<DestructionObserver> destruction_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(TextureManager);
 };