Refactor web shell integration tests utilities.

ios/web/public/test/earl_grey/web_view_matchers.h

Index: ios/web/public/test/earl_grey/web_view_matchers.h
diff --git a/ios/web/shell/test/web_view_matchers.h b/ios/web/public/test/earl_grey/web_view_matchers.h
similarity index 57%
rename from ios/web/shell/test/web_view_matchers.h
rename to ios/web/public/test/earl_grey/web_view_matchers.h
index 0ba394e44b114a81108f77f671b878c52940f9e6..397b45a78c1c2310bbc9ab40980e30d37c7a3196 100644
--- a/ios/web/shell/test/web_view_matchers.h
+++ b/ios/web/public/test/earl_grey/web_view_matchers.h
@@ -4,16 +4,19 @@
 
 #import <EarlGrey/EarlGrey.h>
 
+#include "ios/web/public/web_state/web_state.h"
+
 namespace web {
 
-// Shorthand for GREYMatchers::matcherForWebViewContainingText.
-id<GREYMatcher> webViewContainingText(NSString* text);
+// Shorthand for GREYMatchers::matcherForWebViewContainingText:inWebState.
+id<GREYMatcher> webViewContainingText(NSString* text, web::WebState* webState);
 
 }  // namespace web
 
 @interface GREYMatchers (WebViewAdditions)
 
 // Matcher for WKWebView containing |text|.
-+ (id<GREYMatcher>)matcherForWebViewContainingText:(NSString*)text;
++ (id<GREYMatcher>)matcherForWebViewContainingText:(NSString*)text
+                                        inWebState:(web::WebState*)webState;
 
-@end
+@end