Enable unfold_short_circuits workaround on Apple.

include/platform/FeaturesGL.h

@@ -348,6 +348,13 @@ struct FeaturesGL : FeatureSetBase
         "rgb_dxt1_textures_sample_zero_alpha", FeatureCategory::OpenGLWorkarounds,
         "Sampling BLACK texels from RGB DXT1 textures returns transparent black on Mac.", &members,
         "http://anglebug.com/3729"};
+
+    // Mac incorrectly executes both sides of && and || expressions when they should short-circuit.
+    Feature unfoldShortCircuits = {
+        "unfold_short_circuits", FeatureCategory::OpenGLWorkarounds,
+        "Mac incorrectly executes both sides of && and || expressions when they should "
+        "short-circuit.",
+        &members, "http://anglebug.com/482"};
 };
 
 inline FeaturesGL::FeaturesGL()  = default;

src/libANGLE/renderer/gl/ShaderGL.cpp

@@ -338,6 +338,11 @@ std::shared_ptr<WaitableCompileEvent> ShaderGL::compile(const gl::Context *conte
         additionalOptions |= SH_ADD_BASE_VERTEX_TO_VERTEX_ID;
     }
 
+    if (features.unfoldShortCircuits.enabled)
+    {
+        additionalOptions |= SH_UNFOLD_SHORT_CIRCUIT;
+    }
+
     options |= additionalOptions;
 
     auto workerThreadPool = context->getWorkerThreadPool();

src/libANGLE/renderer/gl/renderergl_utils.cpp

@@ -1562,6 +1562,8 @@ void InitializeFeatures(const FunctionsGL *functions, angle::FeaturesGL *feature
                             IsApple() || (IsWindows() && isAMD))
 
     ANGLE_FEATURE_CONDITION(features, rgbDXT1TexturesSampleZeroAlpha, IsApple())
+
+    ANGLE_FEATURE_CONDITION(features, unfoldShortCircuits, IsApple())
 }
 
 void InitializeFrontendFeatures(const FunctionsGL *functions, angle::FrontendFeatures *features)