Fix flaky LayerTreeHostCopyRequestTestDeleteTexture test.

cc/resources/video_resource_updater_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/resources/video_resource_updater.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/bind.h"
@@ skipping 37 matching lines @@
   GLuint createTexture() override {
     ++created_texture_count_;
     return TestWebGraphicsContext3D::createTexture();
   }
 
   void deleteTexture(GLuint texture) override {
     --created_texture_count_;
     TestWebGraphicsContext3D::deleteTexture(texture);
   }
 
+  void deleteTextures(GLsizei count, const GLuint* ids) override {
+    created_texture_count_ -= count;
+    TestWebGraphicsContext3D::deleteTextures(count, ids);
+  }
+
   int UploadCount() { return upload_count_; }
   void ResetUploadCount() { upload_count_ = 0; }
 
   int TextureCreationCount() { return created_texture_count_; }
   void ResetTextureCreationCount() { created_texture_count_ = 0; }
 
   bool WasImmutableTextureCreated() { return immutable_texture_created_; }
   void ResetImmutableTextureCreated() { immutable_texture_created_ = false; }
 
  private:
@@ skipping 498 matching lines @@
           FromHalfFloat(half_floats[i] + 1) - FromHalfFloat(half_floats[i]);
       EXPECT_NEAR(FromHalfFloat(half_floats[i]), expected_value,
                   expected_precision)
           << "i = " << i << " bits = " << bits;
     }
   }
 }
 
 }  // namespace
 }  // namespace cc