Implement more of the ArCore API in arcore_shim.cc

This CL implements the ArLightEstimate and ArImage functions, as well as
more of the ArConfig and ArFrame methods.

Additionally, it cleans up some of the preprocessor weirdness,
preferring to use a higher-order macro rather than redefining an
existing macro.

Bug: 1034135
Change-Id: I95cd5101888b53d54abe432ea94d993b6678328e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1972909Reviewed-by: Piotr Bialecki <bialpio@chromium.org>
Commit-Queue: Will Cassella <cassew@google.com>
Cr-Commit-Position: refs/heads/master@{#726054}

chrome/browser/android/vr/arcore_device/arcore_shim.h

@@ -5,6 +5,8 @@
 #ifndef CHROME_BROWSER_ANDROID_VR_ARCORE_DEVICE_ARCORE_SHIM_H_
 #define CHROME_BROWSER_ANDROID_VR_ARCORE_DEVICE_ARCORE_SHIM_H_
 
+#include <string>
+
 namespace vr {
 
 // TODO(https://crbug.com/917526): add support for unloading the SDK.