Make FindInPageRectFromRange to use ComputeTextRect()

This function changes FindInPageRectFromRange to use |ComputeTextRect()| instead
of |LayoutObject::AbsoluteBoundingBoxRectForRange()|, which is a wrapper of
|ComputeTextRect()|, to simplify source code.

Following patch will get rid of |AbsoluteBoundingBoxRectForRange()|.

Change-Id: I2c9d3d198a95fa53b943fd9cbdef0a93d0d3ddb3
Reviewed-on: https://chromium-review.googlesource.com/c/1451505Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
Commit-Queue: Yoshifumi Inoue <yosin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#629005}

third_party/blink/renderer/core/editing/finder/find_in_page_coordinates.cc

@@ -33,6 +33,7 @@
 #include "third_party/blink/renderer/core/dom/node.h"
 #include "third_party/blink/renderer/core/dom/range.h"
 #include "third_party/blink/renderer/core/editing/ephemeral_range.h"
+#include "third_party/blink/renderer/core/editing/visible_units.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
 #include "third_party/blink/renderer/core/frame/local_frame_view.h"
 #include "third_party/blink/renderer/core/layout/layout_block.h"
@@ -147,8 +148,8 @@ FloatRect FindInPageRectFromRange(const EphemeralRange& range) {
   if (!baseLayoutObject)
     return FloatRect();
 
-  return FindInPageRectFromAbsoluteRect(
-      LayoutObject::AbsoluteBoundingBoxRectForRange(range), baseLayoutObject);
+  return FindInPageRectFromAbsoluteRect(ComputeTextFloatRect(range),
+                                        baseLayoutObject);
 }
 
 }  // namespace blink