[ChromeDriver] GetElementRect should allow doubles

Currently, GetElementRect command expects all returned values (x, y,
width, height) to be integers, but in reality they can be non-integer
numbers. This CL fixes the implementation, and improves error messages.

Bug: chromedriver:2545
Change-Id: I8c01f0d7f3de530e5e54b7e698a5583b050b68a3
Reviewed-on: https://chromium-review.googlesource.com/1178759Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Commit-Queue: John Chen <johnchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583851}

chrome/test/chromedriver/element_commands.cc

@@ -504,24 +504,24 @@ Status ExecuteGetElementRect(Session* session,
     return Status(kUnknownError, "could not convert to DictionaryValue");
 
   // grab values
-  int x, y, width, height;
-  if (!location_dict->GetInteger("x", &x))
-    return Status(kUnknownError, "getting size failed to return x");
+  double x, y, width, height;
+  if (!location_dict->GetDouble("x", &x))
+    return Status(kUnknownError, "x coordinate is missing in element location");
 
-  if (!location_dict->GetInteger("y", &y))
-    return Status(kUnknownError, "getting size failed to return y");
+  if (!location_dict->GetDouble("y", &y))
+    return Status(kUnknownError, "y coordinate is missing in element location");
 
-  if (!size_dict->GetInteger("height", &height))
-    return Status(kUnknownError, "getting location failed to return height");
+  if (!size_dict->GetDouble("height", &height))
+    return Status(kUnknownError, "height is missing in element size");
 
-  if (!size_dict->GetInteger("width", &width))
-    return Status(kUnknownError, "getting location failed to return width");
+  if (!size_dict->GetDouble("width", &width))
+    return Status(kUnknownError, "width is missing in element size");
 
   base::DictionaryValue ret;
-  ret.SetInteger("x", x);
-  ret.SetInteger("y", y);
-  ret.SetInteger("width", width);
-  ret.SetInteger("height", height);
+  ret.SetDouble("x", x);
+  ret.SetDouble("y", y);
+  ret.SetDouble("width", width);
+  ret.SetDouble("height", height);
   value->reset(ret.DeepCopy());
   return Status(kOk);
 }