ParallelCompile: Enable worker on GL backend

src/libANGLE/renderer/gl/renderergl_utils.cpp

@@ -1454,7 +1454,11 @@ void GenerateWorkarounds(const FunctionsGL *functions, WorkaroundsGL *workaround
 
     workarounds->dontRelinkProgramsInParallel = IsAndroid() || (IsWindows() && IsIntel(vendor));
 
-    workarounds->disableWorkerContexts = !IsApple();
+    // TODO(jie.a.chen@intel.com): Clean up the bugs.
+    // anglebug.com/3031
+    // crbug.com/922936
+    workarounds->disableWorkerContexts =
+        (IsWindows() && (IsIntel(vendor) || IsAMD(vendor))) || (IsLinux() && IsNvidia(vendor));
 }
 
 void ApplyWorkarounds(const FunctionsGL *functions, gl::Workarounds *workarounds)

src/libANGLE/renderer/gl/wgl/DisplayWGL.cpp

@@ -106,7 +106,6 @@ DisplayWGL::DisplayWGL(const egl::DisplayState &state)
       mD3d11Module(nullptr),
       mD3D11DeviceHandle(nullptr),
       mD3D11Device(nullptr),
-      mHasWorkerContexts(true),
       mUseARBShare(true)
 {}
 
@@ -293,13 +292,6 @@ egl::Error DisplayWGL::initializeImpl(egl::Display *display)
         return egl::EglNotInitialized() << "Intel OpenGL ES drivers are not supported.";
     }
 
-    // Using worker contexts is not currently supported due to bugs in the driver.
-    // http://anglebug.com/3031
-    if (IsAMD(vendor))
-    {
-        mHasWorkerContexts = false;
-    }
-
     // Create DXGI swap chains for windows that come from other processes.  Windows is unable to
     // SetPixelFormat on windows from other processes when a sandbox is enabled.
     HDC nativeDisplay = display->getNativeDisplayId();
@@ -995,11 +987,6 @@ WorkerContext *DisplayWGL::createWorkerContext(std::string *infoLog,
                                                HGLRC sharedContext,
                                                const std::vector<int> &workerContextAttribs)
 {
-    if (!mHasWorkerContexts)
-    {
-        *infoLog += "Has no WorkerContext support.";
-        return nullptr;
-    }
     if (!sharedContext)
     {
         *infoLog += "Unable to create the shared context.";

src/libANGLE/renderer/gl/wgl/DisplayWGL.h

@@ -145,7 +145,6 @@ class DisplayWGL : public DisplayGL
     };
     std::map<IUnknown *, D3DObjectHandle> mRegisteredD3DDevices;
 
-    bool mHasWorkerContexts;
     bool mUseARBShare;
 };