docs fix external substitutions

explict substitutions are required to distiguish words
that preserve underscores

R=caryclark@google.com

Docs-Preview: https://skia.org/?cl=134841
Bug: skia:6898
Change-Id: Id1a5669c180e03e048de3c0251882bd06b297283
Reviewed-on: https://skia-review.googlesource.com/134841
Reviewed-by: Cary Clark <caryclark@skia.org>
Commit-Queue: Cary Clark <caryclark@skia.org>
Auto-Submit: Cary Clark <caryclark@skia.org>
diff --git a/docs/SkIRect_Reference.bmh b/docs/SkIRect_Reference.bmh
index f3c269b..bcca39e 100644
--- a/docs/SkIRect_Reference.bmh
+++ b/docs/SkIRect_Reference.bmh
@@ -790,7 +790,7 @@
 #Param dx  offset added to fLeft and fRight ##
 #Param dy  offset added to fTop and fBottom ##
 
-#Return IRect offset in x or y, with original width and height ##
+#Return IRect offset by dx and dy, with original width and height ##
 
 #Example
     SkIRect rect = { 10, 50, 20, 60 };
@@ -1129,10 +1129,10 @@
 Returns true if IRect contains construction.
 Returns false if IRect is empty or construction is empty.
 
-#Param left  x minimum of constructed IRect ##
-#Param top  y minimum of constructed IRect ##
-#Param right  x maximum of constructed IRect ##
-#Param bottom  y maximum of constructed IRect ##
+#Param left  x-axis minimum of constructed IRect ##
+#Param top  y-axis minimum of constructed IRect ##
+#Param right  x-axis maximum of constructed IRect ##
+#Param bottom  y-axis maximum of constructed IRect ##
 
 #Return true if all sides of IRect are outside construction ##
 
@@ -1241,10 +1241,10 @@
 
 Return is undefined if IRect is empty or construction is empty.
 
-#Param left  x minimum of constructed IRect ##
-#Param top  y minimum of constructed IRect ##
-#Param right  x maximum of constructed IRect ##
-#Param bottom  y maximum of constructed IRect ##
+#Param left  x-axis minimum of constructed IRect ##
+#Param top  y-axis minimum of constructed IRect ##
+#Param right  x-axis maximum of constructed IRect ##
+#Param bottom  y-axis maximum of constructed IRect ##
 
 #Return true if all sides of IRect are outside construction ##
 
@@ -1412,10 +1412,10 @@
 
 Returns false if either construction or IRect is empty, leaving IRect unchanged.
 
-#Param left  x minimum of constructed IRect ##
-#Param top  y minimum of constructed IRect ##
-#Param right  x maximum of constructed IRect ##
-#Param bottom  y maximum of constructed IRect ##
+#Param left  x-axis minimum of constructed IRect ##
+#Param top  y-axis minimum of constructed IRect ##
+#Param right  x-axis maximum of constructed IRect ##
+#Param bottom  y-axis maximum of constructed IRect ##
 
 #Return true if construction and IRect have area in common ##
 
@@ -1510,10 +1510,10 @@
 Has no effect if construction is empty. Otherwise, if IRect is empty, sets
 IRect to construction.
 
-#Param left  x minimum of constructed IRect ##
-#Param top  y minimum of constructed IRect ##
-#Param right  x maximum of constructed IRect ##
-#Param bottom  y maximum of constructed IRect ##
+#Param left  x-axis minimum of constructed IRect ##
+#Param top  y-axis minimum of constructed IRect ##
+#Param right  x-axis maximum of constructed IRect ##
+#Param bottom  y-axis maximum of constructed IRect ##
 
 #Example
     SkIRect rect = { 10, 20, 15, 25};