Refactor internal format pixel math methods.

This removes the use of the ErrorOrResult class from these methods.
This will enable more performant Error handling. Also cleans up the
ANGLE_TRY_CHECKED_MATH macro to be more general.

Bug: angleproject:2713
Change-Id: I349947d320907839ca88ec1f9251e6ddc3858a08
Reviewed-on: https://chromium-review.googlesource.com/1128920
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Frank Henigman <fjhenigman@chromium.org>
diff --git a/src/libANGLE/renderer/d3d/FramebufferD3D.cpp b/src/libANGLE/renderer/d3d/FramebufferD3D.cpp
index 222e4c3..b443f9a 100644
--- a/src/libANGLE/renderer/d3d/FramebufferD3D.cpp
+++ b/src/libANGLE/renderer/d3d/FramebufferD3D.cpp
@@ -260,12 +260,12 @@
     const gl::InternalFormat &sizedFormatInfo = gl::GetInternalFormatInfo(format, type);
 
     GLuint outputPitch = 0;
-    ANGLE_TRY_RESULT(sizedFormatInfo.computeRowPitch(type, origArea.width, packState.alignment,
-                                                     packState.rowLength),
-                     outputPitch);
+    ANGLE_TRY_CHECKED_MATH(sizedFormatInfo.computeRowPitch(
+        type, origArea.width, packState.alignment, packState.rowLength, &outputPitch));
+
     GLuint outputSkipBytes = 0;
-    ANGLE_TRY_RESULT(sizedFormatInfo.computeSkipBytes(type, outputPitch, 0, packState, false),
-                     outputSkipBytes);
+    ANGLE_TRY_CHECKED_MATH(
+        sizedFormatInfo.computeSkipBytes(type, outputPitch, 0, packState, false, &outputSkipBytes));
     outputSkipBytes +=
         (area.x - origArea.x) * sizedFormatInfo.pixelBytes + (area.y - origArea.y) * outputPitch;