cc: Allow TestDelegatingOutputSurface to be used for non-pixel tests.

cc/test/layer_tree_pixel_test.h

 // 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.
 
 #ifndef CC_TEST_LAYER_TREE_PIXEL_TEST_H_
 #define CC_TEST_LAYER_TREE_PIXEL_TEST_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 22 matching lines @@
  public:
   enum PixelTestType {
     PIXEL_TEST_GL,
     PIXEL_TEST_SOFTWARE,
   };
 
  protected:
   LayerTreePixelTest();
   ~LayerTreePixelTest() override;
 
+  // LayerTreeTest overrides.
   void InitializeSettings(LayerTreeSettings* settings) override;
   std::unique_ptr<OutputSurface> CreateOutputSurface() override;
 
   virtual std::unique_ptr<CopyOutputRequest> CreateCopyOutputRequest();
 
   void ReadbackResult(std::unique_ptr<CopyOutputResult> result);
 
   void BeginTest() override;
   void SetupTree() override;
   void AfterTest() override;
@@ skipping 21 matching lines @@
                                       scoped_refptr<Layer> content_root,
                                       Layer* target,
                                       base::FilePath file_name);
 
   std::unique_ptr<SkBitmap> CopyTextureMailboxToBitmap(
       const gfx::Size& size,
       const TextureMailbox& texture_mailbox);
 
   void Finish();
 
+  // Allow tests to enlarge the backing texture for a non-root render pass, to
+  // simulate reusing a larger texture from a previous frame for a new
+  // render pass. This should be called before the output surface is bound.
   void set_enlarge_texture_amount(const gfx::Size& enlarge_texture_amount) {
     enlarge_texture_amount_ = enlarge_texture_amount;
   }
 
   // Common CSS colors defined for tests to use.
   static const SkColor kCSSOrange = 0xffffa500;
   static const SkColor kCSSBrown = 0xffa52a2a;
   static const SkColor kCSSGreen = 0xff008000;
 
   gl::DisableNullDrawGLBindings enable_pixel_output_;
   std::unique_ptr<PixelComparator> pixel_comparator_;
   PixelTestType test_type_;
   scoped_refptr<Layer> content_root_;
   Layer* readback_target_;
   base::FilePath ref_file_;
   std::unique_ptr<SkBitmap> result_bitmap_;
   std::vector<scoped_refptr<TextureLayer>> texture_layers_;
   int pending_texture_mailbox_callbacks_;
   gfx::Size enlarge_texture_amount_;
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_LAYER_TREE_PIXEL_TEST_H_