Update CopyTexImage2D to do internal format validation in ES3

gpu/command_buffer/common/gles2_cmd_utils.cc

Index: gpu/command_buffer/common/gles2_cmd_utils.cc
diff --git a/gpu/command_buffer/common/gles2_cmd_utils.cc b/gpu/command_buffer/common/gles2_cmd_utils.cc
index b6533a29cdd18dce7bb8224bcc0582128ad7748b..0f4fe4b88a2feb66a43e455738f7d4bd03f7fcc8 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils.cc
+++ b/gpu/command_buffer/common/gles2_cmd_utils.cc
@@ -1210,6 +1210,23 @@ bool GLES2Util::IsIntegerFormat(uint32_t internal_format) {
           IsSignedIntegerFormat(internal_format));
 }
 
+// static
+bool GLES2Util::IsFloatFormat(uint32_t internal_format) {
+  switch (internal_format) {
+    case GL_R16F:
+    case GL_R32F:
+    case GL_RG16F:
+    case GL_RG32F:
+    case GL_R11F_G11F_B10F:
+    case GL_RGB16F:
+    case GL_RGB32F:
+    case GL_RGBA16F:
+    case GL_RGBA32F:
+      return true;
+    default:
+      return false;
+  }
+}
 
 namespace {