Fix accessibility coordinates within iframes.

content/test/data/accessibility/iframe-coordinates-expected-win.txt

Index: content/test/data/accessibility/iframe-coordinates-expected-win.txt
diff --git a/content/test/data/accessibility/iframe-coordinates-expected-win.txt b/content/test/data/accessibility/iframe-coordinates-expected-win.txt
new file mode 100644
index 0000000000000000000000000000000000000000..c95650a429eb85751efa8dc19aaddb0ecdb2d7e0
--- /dev/null
+++ b/content/test/data/accessibility/iframe-coordinates-expected-win.txt
@@ -0,0 +1,19 @@
+ROLE_SYSTEM_DOCUMENT READONLY FOCUSABLE location=(0, 0) size=(800, 600)
+    IA2_ROLE_SECTION location=(0, 0) size=(300, 150)
+        ROLE_SYSTEM_PUSHBUTTON name='Button' FOCUSABLE location=(25, 25) size=(250, 50)
+    IA2_ROLE_SECTION location=(0, 150) size=(300, 150)
+        ROLE_SYSTEM_PUSHBUTTON name='Button' FOCUSABLE location=(25, 175) size=(250, 50)
+    IA2_ROLE_SECTION location=(0, 300) size=(300, 150)
+        ROLE_SYSTEM_CLIENT FOCUSABLE location=(0, 300) size=(300, 100)
+            IA2_ROLE_SCROLL_PANE location=(0, 0) size=(0, 0)
+                ROLE_SYSTEM_DOCUMENT READONLY FOCUSABLE location=(0, 300) size=(300, 100)
+                    IA2_ROLE_SECTION location=(0, 300) size=(300, 100)
+                        ROLE_SYSTEM_PUSHBUTTON name='Button' FOCUSABLE location=(25, 325) size=(250, 50)
+    IA2_ROLE_SECTION location=(0, 450) size=(300, 150)
+        ROLE_SYSTEM_CLIENT FOCUSABLE location=(0, 450) size=(150, 50)
+            IA2_ROLE_SCROLL_PANE location=(0, 0) size=(0, 0)
+                ROLE_SYSTEM_DOCUMENT READONLY FOCUSABLE location=(0, 450) size=(300, 100)
+                    IA2_ROLE_SECTION location=(-150, 400) size=(300, 100)
+                        ROLE_SYSTEM_PUSHBUTTON name='Button' FOCUSABLE location=(-125, 425) size=(250, 50)
+                ROLE_SYSTEM_SCROLLBAR location=(0, 0) size=(0, 0)
+                ROLE_SYSTEM_SCROLLBAR location=(0, 0) size=(0, 0)