Defer compositor context creation to the thread.

cc/test/test_context_provider.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_TEST_CONTEXT_PROVIDER_H_
 #define CC_TEST_TEST_CONTEXT_PROVIDER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 12 matching lines @@
 namespace cc {
 class TestWebGraphicsContext3D;
 class TestGLES2Interface;
 
 class TestContextProvider : public ContextProvider {
  public:
   typedef base::Callback<std::unique_ptr<TestWebGraphicsContext3D>(void)>
       CreateCallback;
 
   static scoped_refptr<TestContextProvider> Create();
-  // Creates a worker context provider that can be used on any thread. This is
-  // equivalent to: Create(); BindToCurrentThread().
-  static scoped_refptr<TestContextProvider> CreateWorker();
   static scoped_refptr<TestContextProvider> Create(
       std::unique_ptr<TestWebGraphicsContext3D> context);
 
-  bool BindToCurrentThread() override;
-  void DetachFromThread() override;
+  class Factory : public ContextProvider::Factory {
+   public:
+    // Creates a context provider with default capabilities.
+    Factory();
+    // Creates a context provider wrapping the given TestWebGraphicsContext3D.
+    explicit Factory(std::unique_ptr<TestWebGraphicsContext3D> context);
+    // Creates a context provider with the given capabilities.
+    explicit Factory(const gpu::Capabilities& capabilities);
+    // Fails to create a context provider, simulating loss of the gpu channel or
+    // other such error conditions.
+    enum FailCreate { kFailCreate = 1 };
+    explicit Factory(FailCreate);
+
+    ~Factory();
+    scoped_refptr<ContextProvider> CreateContext() override;
+
+   private:

[danakj, 2016/05/17 23:17:15]

Notably I made these private and added constructors so it's harder to use it
wrong, and you can just write MakeUnique<T> once instead of needing an lvalue to
set stuff on.

+    const bool fail_create_ = false;
+    std::unique_ptr<TestWebGraphicsContext3D> context_;
+    const gpu::Capabilities capabilities_;
+
+    DISALLOW_COPY_AND_ASSIGN(Factory);
+  };
+
   gpu::Capabilities ContextCapabilities() override;
   gpu::gles2::GLES2Interface* ContextGL() override;
   gpu::ContextSupport* ContextSupport() override;
   class GrContext* GrContext() override;
   void InvalidateGrContext(uint32_t state) override;
   base::Lock* GetLock() override;
   void DeleteCachedResources() override;
   void SetLostContextCallback(const LostContextCallback& cb) override;
+  void DetachFromThread() override;
 
   TestWebGraphicsContext3D* TestContext3d();
-
-  // This returns the TestWebGraphicsContext3D but is valid to call
-  // before the context is bound to a thread. This is needed to set up
-  // state on the test context before binding. Don't call
-  // InitializeOnCurrentThread on the context returned from this method.
-  TestWebGraphicsContext3D* UnboundTestContext3d();
-
   TestContextSupport* support() { return &support_; }
 
  protected:
   explicit TestContextProvider(
       std::unique_ptr<TestWebGraphicsContext3D> context);
   ~TestContextProvider() override;
 
  private:
   void OnLostContext();
 
   TestContextSupport support_;
 
   std::unique_ptr<TestWebGraphicsContext3D> context3d_;
   std::unique_ptr<TestGLES2Interface> context_gl_;
-  bool bound_;
 
-  base::ThreadChecker main_thread_checker_;
-  base::ThreadChecker context_thread_checker_;
+  base::ThreadChecker thread_checker_;
 
   base::Lock context_lock_;
 
   LostContextCallback lost_context_callback_;
   sk_sp<class GrContext> gr_context_;
 
   base::WeakPtrFactory<TestContextProvider> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TestContextProvider);
 };
 
 }  // namespace cc
 
 #endif  // CC_TEST_TEST_CONTEXT_PROVIDER_H_