Use all available texture units.

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 01fbceee0423baeb2a0411eba34429f844e65db5..0b625a5a3a689d6cece0c24c2f0ad52b20f66861 100644
--- a/src/gpu/gl/GrGLCaps.h
+++ b/src/gpu/gl/GrGLCaps.h
@@ -215,9 +215,12 @@ public:
     /// The maximum number of fragment uniform vectors (GLES has min. 16).
     int maxFragmentUniformVectors() const { return fMaxFragmentUniformVectors; }
 
-    // maximum number of attribute values per vertex
+    /// maximum number of attribute values per vertex
     int maxVertexAttributes() const { return fMaxVertexAttributes; }
 
+    /// maximum number of texture units accessible in the fragment shader.
+    int maxFragmentTextureUnits() const { return fMaxFragmentTextureUnits; }
+
     /// ES requires an extension to support RGBA8 in RenderBufferStorage
     bool rgba8RenderbufferSupport() const { return fRGBA8RenderbufferSupport; }
 
@@ -332,6 +335,7 @@ private:
 
     int fMaxFragmentUniformVectors;
     int fMaxVertexAttributes;
+    int fMaxFragmentTextureUnits;
 
     MSFBOType fMSFBOType;
     CoverageAAType fCoverageAAType;