Break dependency between ChromeClient and WebViewImpl, and ChromeClientImpl.

third_party/WebKit/Source/core/exported/WebViewBase.h

Index: third_party/WebKit/Source/core/exported/WebViewBase.h
diff --git a/third_party/WebKit/Source/core/exported/WebViewBase.h b/third_party/WebKit/Source/core/exported/WebViewBase.h
index 4221b1ae523530abb93db19e01a3beb5a8c5f7aa..c7baf9b7e23bfbe56022af2a6a5465343d0423c3 100644
--- a/third_party/WebKit/Source/core/exported/WebViewBase.h
+++ b/third_party/WebKit/Source/core/exported/WebViewBase.h
@@ -15,6 +15,7 @@
 namespace blink {
 
 class AnimationWorkletProxyClient;
+class ChromeClient;
 class CompositorAnimationHost;
 class CompositorWorkerProxyClient;
 class CompositorAnimationTimeline;
@@ -173,6 +174,8 @@ class WebViewBase : public WebView, public RefCounted<WebViewBase> {
   virtual void SetRootLayer(WebLayer*) = 0;
   virtual CompositorAnimationHost* AnimationHost() const = 0;
   virtual HitTestResult CoreHitTestResultAt(const WebPoint&) = 0;
+
+  virtual class ChromeClient& ChromeClient() const = 0;
 };
 }