GL: Update BufferGL to use ANGLE_GL_TRY.

include/platform/FeaturesGL.h

@@ -492,6 +492,13 @@ struct FeaturesGL : FeatureSetBase
         "Speculative fix for issues on Linux/Wayland where exposing GLX_OML_sync_control renders "
         "Chrome unusable",
         &members, "https://crbug.com/1137851"};
+
+    // Buffers need to maintain a shadow copy of data when buffer data readback is not possible
+    // through the GL API
+    Feature keepBufferShadowCopy = {
+        "keep_buffer_shadow_copy", FeatureCategory::OpenGLWorkarounds,
+        "Maintain a shadow copy of buffer data when the GL API does not permit reading data back.",
+        &members};
 };
 
 inline FeaturesGL::FeaturesGL()  = default;

src/libANGLE/renderer/gl/BufferGL.h

@@ -21,11 +21,11 @@ class StateManagerGL;
 class BufferGL : public BufferImpl
 {
   public:
-    BufferGL(const gl::BufferState &state,
-             const FunctionsGL *functions,
-             StateManagerGL *stateManager);
+    BufferGL(const gl::BufferState &state, GLuint buffer);
     ~BufferGL() override;
 
+    void destroy(const gl::Context *context) override;
+
     angle::Result setData(const gl::Context *context,
                           gl::BufferBinding target,
                           const void *data,
@@ -63,14 +63,10 @@ class BufferGL : public BufferImpl
     size_t mMapOffset;
     size_t mMapSize;
 
-    bool mShadowBufferData;
     angle::MemoryBuffer mShadowCopy;
 
     size_t mBufferSize;
 
-    const FunctionsGL *mFunctions;
-    StateManagerGL *mStateManager;
-
     GLuint mBufferID;
 };
 

src/libANGLE/renderer/gl/ContextGL.cpp

@@ -105,7 +105,12 @@ RenderbufferImpl *ContextGL::createRenderbuffer(const gl::RenderbufferState &sta
 
 BufferImpl *ContextGL::createBuffer(const gl::BufferState &state)
 {
-    return new BufferGL(state, getFunctions(), getStateManager());
+    const FunctionsGL *functions = getFunctions();
+
+    GLuint buffer = 0;
+    functions->genBuffers(1, &buffer);
+
+    return new BufferGL(state, buffer);
 }
 
 VertexArrayImpl *ContextGL::createVertexArray(const gl::VertexArrayState &data)

src/libANGLE/renderer/gl/renderergl_utils.cpp

@@ -1834,6 +1834,8 @@ void InitializeFeatures(const FunctionsGL *functions, angle::FeaturesGL *feature
     // http://crbug.com/1137851
     // Speculative fix for now, leave disabled so users can enable it via flags.
     ANGLE_FEATURE_CONDITION(features, disableSyncControlSupport, false);
+
+    ANGLE_FEATURE_CONDITION(features, keepBufferShadowCopy, !CanMapBufferForRead(functions));
 }
 
 void InitializeFrontendFeatures(const FunctionsGL *functions, angle::FrontendFeatures *features)