[rb] checking wrong public method for full page screenshots

Author: titusfortner

rb/lib/selenium/webdriver/common/takes_screenshot.rb

@@ -49,7 +49,7 @@ def save_screenshot(png_path, full_page: false)
       # @api public
 
       def screenshot_as(format, full_page: false)
-        if full_page && !respond_to?(:full_page)
+        if full_page && !respond_to?(:save_full_page_screenshot)
           raise Error::UnsupportedOperationError, "Full Page Screenshots are not supported for #{inspect}"
         end
 

rb/spec/integration/selenium/webdriver/takes_screenshot_spec.rb

@@ -110,7 +110,8 @@ def save_screenshot_and_assert(source, path)
           expect(height).to be > viewport_height
         end
 
-        it 'does not take full page screenshot', except: {browser: :firefox} do
+        it 'does not take full page screenshot', only: {browser: %i[chrome edge safari safari_preview],
+                                                        reason: 'these browsers do not implement this feature'} do
           expect {
             driver.save_screenshot path, full_page: true
           }.to raise_exception(Error::UnsupportedOperationError, /Full Page Screenshots are not supported/)