Handle cases where the expected and got strings are both substrings of the test source. In this situation its better to use the longer option.
Fixes cases where fix-tests would keep on adding junk to an EXPECT_EQ string
Change-Id: I800d0d08178d01743b3587527830aefce3f3152e
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/54240
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
d80bb9d997