To answer the question, I followed these steps:

<ul>
  <li><b>Identified the relevant indicator:</b> I searched for indicators related to "surface area" and found "Surface area (sq. km)" which represents a country's total area including inland water bodies.</li>
  <li><b>Obtained the indicator code:</b> I retrieved the specific code for "Surface area (sq. km)" which is "AG.SRF.TOTL.K2".</li>
  <li><b>Determined the countries in Eastern Asia:</b> I listed the countries in the Eastern Asia region, including China, Hong Kong, Japan, South Korea, Macau, Mongolia, and North Korea.</li>
  <li><b>Collected 2005 surface area data:</b> I gathered the surface area values for each of these countries for the year 2005 to find which had the highest value.</li>
  <li><b>Identified the country with the highest surface area in 2005:</b> China had the largest surface area in 2005 among these countries.</li>
</ul>

In summary, I first pinpointed the correct indicator and region, then compared the 2005 surface area values of Eastern Asian countries to find the largest. The country with the highest surface area in 2005 was China.

The final answer is that the country in Eastern Asia with the highest surface area in 2005 was China, and its surface area in 2012 is the value to be reported.