Command buffer should not report depth_texture on pure ES3 without depth_texture extension.

third_party/WebKit/Source/modules/webgl/WebGLDepthTexture.cpp

Index: third_party/WebKit/Source/modules/webgl/WebGLDepthTexture.cpp
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLDepthTexture.cpp b/third_party/WebKit/Source/modules/webgl/WebGLDepthTexture.cpp
index 17b3319638dd8a6e8eda386a02e1ed7dff0c5d93..f29ea4bfcf7c4637eafb3c54b0cbcc5b18b497be 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLDepthTexture.cpp
+++ b/third_party/WebKit/Source/modules/webgl/WebGLDepthTexture.cpp
@@ -55,9 +55,7 @@ bool WebGLDepthTexture::supported(WebGLRenderingContextBase* context)
     // textures unless a packed depth/stencil format is available.
     if (!extensionsUtil->supportsExtension("GL_OES_packed_depth_stencil"))
         return false;
-    return extensionsUtil->supportsExtension("GL_CHROMIUM_depth_texture")
-        || extensionsUtil->supportsExtension("GL_OES_depth_texture")
-        || extensionsUtil->supportsExtension("GL_ARB_depth_texture");
+    return extensionsUtil->supportsExtension("GL_CHROMIUM_depth_texture");
 }
 
 const char* WebGLDepthTexture::extensionName()