Add GL indirect drawing APIs

src/gpu/gl/GrGLCaps.h

Index: src/gpu/gl/GrGLCaps.h
diff --git a/src/gpu/gl/GrGLCaps.h b/src/gpu/gl/GrGLCaps.h
index 044ecce81438c5f67494b008abd16e890baeb8a4..abfcc285b77b083dd33bc4732b320a14566b8f9f 100644
--- a/src/gpu/gl/GrGLCaps.h
+++ b/src/gpu/gl/GrGLCaps.h
@@ -283,6 +283,17 @@ public:
     /// Can we call glDisable(GL_MULTISAMPLE)?
     bool multisampleDisableSupport() const { return fMultisampleDisableSupport; }
 
+    /// Is there support for glDraw*Indirect? Note that the baseInstance fields of indirect draw
+    /// commands cannot be used unless we have base instance support.
+    bool drawIndirectSupport() const { return fDrawIndirectSupport; }
+
+    /// Is there support for glMultiDraw*Indirect? Note that the baseInstance fields of indirect
+    /// draw commands cannot be used unless we have base instance support.
+    bool multiDrawIndirectSupport() const { return fMultiDrawIndirectSupport; }
+
+    /// Are the baseInstance fields supported in indirect draw commands?
+    bool baseInstanceSupport() const { return fBaseInstanceSupport; }
+
     /// Use indices or vertices in CPU arrays rather than VBOs for dynamic content.
     bool useNonVBOVertexAndIndexDynamicData() const { return fUseNonVBOVertexAndIndexDynamicData; }
 
@@ -378,6 +389,9 @@ private:
     bool fDebugSupport : 1;
     bool fES2CompatibilitySupport : 1;
     bool fMultisampleDisableSupport : 1;
+    bool fDrawIndirectSupport : 1;
+    bool fMultiDrawIndirectSupport : 1;
+    bool fBaseInstanceSupport : 1;
     bool fUseNonVBOVertexAndIndexDynamicData : 1;
     bool fIsCoreProfile : 1;
     bool fBindFragDataLocationSupport : 1;