cc: Add an integration test for what scale we draw with after pinching

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 eda6f0f222d6f6327ea39a8e9d0829769522ca70..80914bf25ac3b81e1ed244f447727f5e8aec3a01 100644
--- a/cc/test/test_web_graphics_context_3d.h
+++ b/cc/test/test_web_graphics_context_3d.h
@@ -354,6 +354,11 @@ class TestWebGraphicsContext3D {
     test_support_ = test_support;
   }
 
+  // Set this to 1 to make async texture uploads complete.
+  void set_query_result_available_ext(int value) {
+    query_result_available_ext_ = value;
+  }
+
   int width() const { return width_; }
   int height() const { return height_; }
   bool reshape_called() const { return reshape_called_; }
@@ -457,6 +462,7 @@ class TestWebGraphicsContext3D {
   UpdateType last_update_type_;
   unsigned next_insert_sync_point_;
   unsigned last_waited_sync_point_;
+  int query_result_available_ext_;
 
   unsigned bound_buffer_;
   TextureTargets texture_targets_;