Revert of Allow canvases to be GPU-accelerated in Workers

third_party/WebKit/Source/platform/graphics/gpu/SharedGpuContext.cpp

Index: third_party/WebKit/Source/platform/graphics/gpu/SharedGpuContext.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/gpu/SharedGpuContext.cpp b/third_party/WebKit/Source/platform/graphics/gpu/SharedGpuContext.cpp
deleted file mode 100644
index 8294d3c910c581bc9a835ca2c4dbed3bd27c771f..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/platform/graphics/gpu/SharedGpuContext.cpp
+++ /dev/null
@@ -1,103 +0,0 @@
-// Copyright 2016 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 "platform/graphics/gpu/SharedGpuContext.h"
-
-#include "gpu/command_buffer/client/gles2_interface.h"
-#include "platform/CrossThreadFunctional.h"
-#include "platform/WaitableEvent.h"
-#include "public/platform/Platform.h"
-#include "public/platform/WebGraphicsContext3DProvider.h"
-#include "public/platform/WebTaskRunner.h"
-
-namespace blink {
-
-SharedGpuContext* SharedGpuContext::getInstanceForCurrentThread()
-{
-    DEFINE_THREAD_SAFE_STATIC_LOCAL(ThreadSpecific<SharedGpuContext>, threadSpecificInstance, new ThreadSpecific<SharedGpuContext>);
-    return threadSpecificInstance;
-}
-
-SharedGpuContext::SharedGpuContext()
-    : m_contextId(kNoSharedContext)
-{
-    createContextProvider();
-}
-
-void SharedGpuContext::createContextProviderOnMainThread(WaitableEvent* waitableEvent)
-{
-    DCHECK(isMainThread());
-    Platform::ContextAttributes contextAttributes;
-    contextAttributes.webGLVersion = 1; // GLES2
-    Platform::GraphicsInfo graphicsInfo;
-    m_contextProvider = wrapUnique(Platform::current()->createOffscreenGraphicsContext3DProvider(
-        contextAttributes, WebURL(), nullptr, &graphicsInfo));
-    if (waitableEvent)
-        waitableEvent->signal();
-}
-
-void SharedGpuContext::createContextProvider()
-{
-    std::unique_ptr<WebGraphicsContext3DProvider> oldContextProvider = std::move(m_contextProvider);
-    if (isMainThread()) {
-        m_contextProvider = wrapUnique(blink::Platform::current()->createSharedOffscreenGraphicsContext3DProvider());
-    } else {
-        // This synchronous round-trip to the main thread is the reason why SharedGpuContext
-        // encasulates the context provider: so we only have to do this once per thread.
-        WaitableEvent waitableEvent;
-        WebTaskRunner* taskRunner = Platform::current()->mainThread()->getWebTaskRunner();
-            taskRunner->postTask(BLINK_FROM_HERE, crossThreadBind(&SharedGpuContext::createContextProviderOnMainThread, crossThreadUnretained(this), crossThreadUnretained(&waitableEvent)));
-        waitableEvent.wait();
-        if (m_contextProvider && !m_contextProvider->bindToCurrentThread())
-            m_contextProvider = nullptr;
-    }
-
-    if (m_contextProvider) {
-        m_contextId++;
-        // In the unlikely event of an overflow...
-        if (m_contextId == kNoSharedContext)
-            m_contextId++;
-    } else {
-        m_contextProvider = std::move(oldContextProvider);
-    }
-}
-
-unsigned SharedGpuContext::contextId()
-{
-    SharedGpuContext* thisPtr = getInstanceForCurrentThread();
-    return thisPtr->m_contextId;
-}
-
-gpu::gles2::GLES2Interface* SharedGpuContext::gl()
-{
-    SharedGpuContext* thisPtr = getInstanceForCurrentThread();
-    if (thisPtr->m_contextProvider)
-        return thisPtr->m_contextProvider->contextGL();
-    return nullptr;
-}
-
-GrContext* SharedGpuContext::gr()
-{
-    SharedGpuContext* thisPtr = getInstanceForCurrentThread();
-    if (thisPtr->m_contextProvider)
-        return thisPtr->m_contextProvider->grContext();
-    return nullptr;
-}
-
-bool SharedGpuContext::isValid()
-{
-    SharedGpuContext* thisPtr = getInstanceForCurrentThread();
-    if (!thisPtr->m_contextProvider)
-        return false;
-    return thisPtr->m_contextProvider->contextGL()->GetGraphicsResetStatusKHR() == GL_NO_ERROR;
-}
-
-bool SharedGpuContext::restore()
-{
-    if (!isValid())
-        getInstanceForCurrentThread()->createContextProvider();
-    return isValid();
-}
-
-} // blink