ResourceProvider should be able to avoid allocating immutable textures.

cc/test/test_web_graphics_context_3d.h

Index: cc/test/test_web_graphics_context_3d.h
diff --git a/cc/test/test_web_graphics_context_3d.h b/cc/test/test_web_graphics_context_3d.h
index 5e876ef258945a3fd137548e6932ec58d3713518..3689e9abf4ae0f6ccdaf508e9e33b2d41139bc64 100644
--- a/cc/test/test_web_graphics_context_3d.h
+++ b/cc/test/test_web_graphics_context_3d.h
@@ -206,6 +206,9 @@ class TestWebGraphicsContext3D : public FakeWebGraphicsContext3D {
   void set_support_compressed_texture_etc1(bool support) {
     test_capabilities_.texture_format_etc1 = support;
   }
+  void set_support_texture_storage(bool support) {
+    test_capabilities_.texture_storage = support;
+  }
 
   // When this context is lost, all contexts in its share group are also lost.
   void add_share_group_context(blink::WebGraphicsContext3D* context3d) {