[ios] Expose API for "unrealized" WebState

Add new methods to WebState and WebStateObserver necessary to
expose the new "unrealized" state of the WebState instances.
As the feature is not yet implemented, the methods are stubs,
but this allow converting client code.

Add unit tests for the new method of WebStateObserverBridge
(and also test for the few untested methods). Sort the methods
and properties of the test objects (in the same order as the
methods of WebStateObserver).

Bug: 1264453
Change-Id: I6a8b2334940a60e6e6311f2d9ee718b75ed46778
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3260613
Reviewed-by: Gauthier Ambard <[email protected]>
Commit-Queue: Sylvain Defresne <[email protected]>
Cr-Commit-Position: refs/heads/main@{#939340}

ios/web/public/test/fakes/crw_fake_web_state_observer.h

@@ -18,14 +18,24 @@
 // Arguments passed to |webState:didStartNavigation:|.
 @property(nonatomic, readonly)
     web::TestDidStartNavigationInfo* didStartNavigationInfo;
+// Arguments passed to |webState:didRedirectNavigation:|.
+@property(nonatomic, readonly)
+    web::TestDidRedirectNavigationInfo* didRedirectNavigationInfo;
 // Arguments passed to |webState:didFinishNavigation:|.
 @property(nonatomic, readonly)
     web::TestDidFinishNavigationInfo* didFinishNavigationInfo;
+// Arguments passed to |webStateDidStartLoading:|.
+@property(nonatomic, readonly) web::TestStartLoadingInfo* startLoadingInfo;
+// Arguments passed to |webStateDidStopLoading:|.
+@property(nonatomic, readonly) web::TestStopLoadingInfo* stopLoadingInfo;
 // Arguments passed to |webState:didLoadPageWithSuccess:|.
 @property(nonatomic, readonly) web::TestLoadPageInfo* loadPageInfo;
 // Arguments passed to |webState:didChangeLoadingProgress:|.
 @property(nonatomic, readonly)
     web::TestChangeLoadingProgressInfo* changeLoadingProgressInfo;
+// Arguments passed to |webStateDidChangeBackForwardState:|.
+@property(nonatomic, readonly)
+    web::TestDidChangeBackForwardStateInfo* changeBackForwardStateInfo;
 // Arguments passed to |webStateDidChangeTitle:|.
 @property(nonatomic, readonly) web::TestTitleWasSetInfo* titleWasSetInfo;
 // Arguments passed to |webStateDidChangeVisibleSecurityState:|.
@@ -34,16 +44,15 @@
 // Arguments passed to |webState:didUpdateFaviconURLCandidates|.
 @property(nonatomic, readonly)
     web::TestUpdateFaviconUrlCandidatesInfo* updateFaviconUrlCandidatesInfo;
-// Arguments passed to |webState:renderProcessGoneForWebState:|.
+// Arguments passed to |renderProcessGoneForWebState:|.
 @property(nonatomic, readonly)
     web::TestRenderProcessGoneInfo* renderProcessGoneInfo;
+// Arguments passed to |webStateRealized:|.
+@property(nonatomic, readonly)
+    web::TestWebStateRealizedInfo* webStateRealizedInfo;
 // Arguments passed to |webStateDestroyed:|.
 @property(nonatomic, readonly)
     web::TestWebStateDestroyedInfo* webStateDestroyedInfo;
-// Arguments passed to |webStateDidStopLoading:|.
-@property(nonatomic, readonly) web::TestStopLoadingInfo* stopLoadingInfo;
-// Arguments passed to |webStateDidStartLoading:|.
-@property(nonatomic, readonly) web::TestStartLoadingInfo* startLoadingInfo;
 
 @end
 

ios/web/public/test/fakes/crw_fake_web_state_observer.mm

@@ -15,26 +15,30 @@
 #error "This file requires ARC support."
 #endif
 
-namespace web {
-TestUpdateFaviconUrlCandidatesInfo::TestUpdateFaviconUrlCandidatesInfo() {}
-TestUpdateFaviconUrlCandidatesInfo::~TestUpdateFaviconUrlCandidatesInfo() =
-    default;
-}
-
 @implementation CRWFakeWebStateObserver {
   // Arguments passed to |webStateWasShown:|.
   std::unique_ptr<web::TestWasShownInfo> _wasShownInfo;
   // Arguments passed to |webStateWasHidden:|.
   std::unique_ptr<web::TestWasHiddenInfo> _wasHiddenInfo;
   // Arguments passed to |webState:didStartNavigation:|.
   std::unique_ptr<web::TestDidStartNavigationInfo> _didStartNavigationInfo;
+  // Arguments passed to |webState:didRedirectNavigation:|.
+  std::unique_ptr<web::TestDidRedirectNavigationInfo>
+      _didRedirectNavigationInfo;
   // Arguments passed to |webState:didFinishNavigationForURL:|.
   std::unique_ptr<web::TestDidFinishNavigationInfo> _didFinishNavigationInfo;
+  // Arguments passed to |webStateDidStartLoading:|.
+  std::unique_ptr<web::TestStartLoadingInfo> _startLoadingInfo;
+  // Arguments passed to |webStateDidStopLoading:|.
+  std::unique_ptr<web::TestStopLoadingInfo> _stopLoadingInfo;
   // Arguments passed to |webState:didLoadPageWithSuccess:|.
   std::unique_ptr<web::TestLoadPageInfo> _loadPageInfo;
   // Arguments passed to |webState:didChangeLoadingProgress:|.
   std::unique_ptr<web::TestChangeLoadingProgressInfo>
       _changeLoadingProgressInfo;
+  // Arguments passed to |webStateDidChangeBackForwardState:|.
+  std::unique_ptr<web::TestDidChangeBackForwardStateInfo>
+      _changeBackForwardStateInfo;
   // Arguments passed to |webStateDidChangeTitle:|.
   std::unique_ptr<web::TestTitleWasSetInfo> _titleWasSetInfo;
   // Arguments passed to |webStateDidChangeVisibleSecurityState:|.
@@ -45,12 +49,10 @@ @implementation CRWFakeWebStateObserver {
       _updateFaviconUrlCandidatesInfo;
   // Arguments passed to |webState:renderProcessGoneForWebState:|.
   std::unique_ptr<web::TestRenderProcessGoneInfo> _renderProcessGoneInfo;
+  // Arguments passed to |webStateRealized:|.
+  std::unique_ptr<web::TestWebStateRealizedInfo> _webStateRealizedInfo;
   // Arguments passed to |webStateDestroyed:|.
   std::unique_ptr<web::TestWebStateDestroyedInfo> _webStateDestroyedInfo;
-  // Arguments passed to |webStateDidStopLoading:|.
-  std::unique_ptr<web::TestStopLoadingInfo> _stopLoadingInfo;
-  // Arguments passed to |webStateDidStartLoading:|.
-  std::unique_ptr<web::TestStartLoadingInfo> _startLoadingInfo;
 }
 
 - (web::TestWasShownInfo*)wasShownInfo {
@@ -65,10 +67,22 @@ @implementation CRWFakeWebStateObserver {
   return _didStartNavigationInfo.get();
 }
 
+- (web::TestDidRedirectNavigationInfo*)didRedirectNavigationInfo {
+  return _didRedirectNavigationInfo.get();
+}
+
 - (web::TestDidFinishNavigationInfo*)didFinishNavigationInfo {
   return _didFinishNavigationInfo.get();
 }
 
+- (web::TestStartLoadingInfo*)startLoadingInfo {
+  return _startLoadingInfo.get();
+}
+
+- (web::TestStopLoadingInfo*)stopLoadingInfo {
+  return _stopLoadingInfo.get();
+}
+
 - (web::TestLoadPageInfo*)loadPageInfo {
   return _loadPageInfo.get();
 }
@@ -77,6 +91,10 @@ @implementation CRWFakeWebStateObserver {
   return _changeLoadingProgressInfo.get();
 }
 
+- (web::TestDidChangeBackForwardStateInfo*)changeBackForwardStateInfo {
+  return _changeBackForwardStateInfo.get();
+}
+
 - (web::TestTitleWasSetInfo*)titleWasSetInfo {
   return _titleWasSetInfo.get();
 }
@@ -94,16 +112,12 @@ @implementation CRWFakeWebStateObserver {
   return _renderProcessGoneInfo.get();
 }
 
-- (web::TestWebStateDestroyedInfo*)webStateDestroyedInfo {
-  return _webStateDestroyedInfo.get();
+- (web::TestWebStateRealizedInfo*)webStateRealizedInfo {
+  return _webStateRealizedInfo.get();
 }
 
-- (web::TestStopLoadingInfo*)stopLoadingInfo {
-  return _stopLoadingInfo.get();
-}
-
-- (web::TestStartLoadingInfo*)startLoadingInfo {
-  return _startLoadingInfo.get();
+- (web::TestWebStateDestroyedInfo*)webStateDestroyedInfo {
+  return _webStateDestroyedInfo.get();
 }
 
 #pragma mark CRWWebStateObserver methods -
@@ -133,6 +147,22 @@ - (void)webState:(web::WebState*)webState
   _didStartNavigationInfo->context = std::move(context);
 }
 
+- (void)webState:(web::WebState*)webState
+    didRedirectNavigation:(web::NavigationContext*)navigation {
+  ASSERT_TRUE(!navigation->GetError() || !navigation->IsSameDocument());
+  _didRedirectNavigationInfo =
+      std::make_unique<web::TestDidRedirectNavigationInfo>();
+  _didRedirectNavigationInfo->web_state = webState;
+  std::unique_ptr<web::NavigationContextImpl> context =
+      web::NavigationContextImpl::CreateNavigationContext(
+          navigation->GetWebState(), navigation->GetUrl(),
+          navigation->HasUserGesture(), navigation->GetPageTransition(),
+          navigation->IsRendererInitiated());
+  context->SetIsSameDocument(navigation->IsSameDocument());
+  context->SetError(navigation->GetError());
+  _didRedirectNavigationInfo->context = std::move(context);
+}
+
 - (void)webState:(web::WebState*)webState
     didFinishNavigation:(web::NavigationContext*)navigation {
   ASSERT_TRUE(!navigation->GetError() || !navigation->IsSameDocument());
@@ -149,6 +179,16 @@ - (void)webState:(web::WebState*)webState
   _didFinishNavigationInfo->context = std::move(context);
 }
 
+- (void)webStateDidStartLoading:(web::WebState*)webState {
+  _startLoadingInfo = std::make_unique<web::TestStartLoadingInfo>();
+  _startLoadingInfo->web_state = webState;
+}
+
+- (void)webStateDidStopLoading:(web::WebState*)webState {
+  _stopLoadingInfo = std::make_unique<web::TestStopLoadingInfo>();
+  _stopLoadingInfo->web_state = webState;
+}
+
 - (void)webState:(web::WebState*)webState didLoadPageWithSuccess:(BOOL)success {
   _loadPageInfo = std::make_unique<web::TestLoadPageInfo>();
   _loadPageInfo->web_state = webState;
@@ -168,6 +208,12 @@ - (void)webStateDidChangeTitle:(web::WebState*)webState {
   _titleWasSetInfo->web_state = webState;
 }
 
+- (void)webStateDidChangeBackForwardState:(web::WebState*)webState {
+  _changeBackForwardStateInfo =
+      std::make_unique<web::TestDidChangeBackForwardStateInfo>();
+  _changeBackForwardStateInfo->web_state = webState;
+}
+
 - (void)webStateDidChangeVisibleSecurityState:(web::WebState*)webState {
   _didChangeVisibleSecurityStateInfo =
       std::make_unique<web::TestDidChangeVisibleSecurityStateInfo>();
@@ -188,19 +234,14 @@ - (void)renderProcessGoneForWebState:(web::WebState*)webState {
   _renderProcessGoneInfo->web_state = webState;
 }
 
+- (void)webStateRealized:(web::WebState*)webState {
+  _webStateRealizedInfo = std::make_unique<web::TestWebStateRealizedInfo>();
+  _webStateRealizedInfo->web_state = webState;
+}
+
 - (void)webStateDestroyed:(web::WebState*)webState {
   _webStateDestroyedInfo = std::make_unique<web::TestWebStateDestroyedInfo>();
   _webStateDestroyedInfo->web_state = webState;
 }
 
-- (void)webStateDidStopLoading:(web::WebState*)webState {
-  _stopLoadingInfo = std::make_unique<web::TestStopLoadingInfo>();
-  _stopLoadingInfo->web_state = webState;
-}
-
-- (void)webStateDidStartLoading:(web::WebState*)webState {
-  _startLoadingInfo = std::make_unique<web::TestStartLoadingInfo>();
-  _startLoadingInfo->web_state = webState;
-}
-
 @end

ios/web/public/test/fakes/fake_web_state.h

@@ -37,6 +37,8 @@ class FakeWebState : public WebState {
   OnceGetter CreateDefaultOnceGetter() override;
   WebStateDelegate* GetDelegate() override;
   void SetDelegate(WebStateDelegate* delegate) override;
+  bool IsRealized() const final;
+  WebState* ForceRealized() final;
   bool IsWebUsageEnabled() const override;
   void SetWebUsageEnabled(bool enabled) override;
   UIView* GetView() override;

ios/web/public/test/fakes/fake_web_state.mm

@@ -83,6 +83,15 @@
 
 void FakeWebState::SetDelegate(WebStateDelegate* delegate) {}
 
+bool FakeWebState::IsRealized() const {
+  // FakeWebState cannot be unrealized.
+  return true;
+}
+
+WebState* FakeWebState::ForceRealized() {
+  return this;
+}
+
 BrowserState* FakeWebState::GetBrowserState() const {
   return browser_state_;
 }

ios/web/public/test/fakes/fake_web_state_observer_util.h

@@ -35,6 +35,14 @@ struct TestDidStartNavigationInfo {
   std::unique_ptr<web::NavigationContext> context;
 };
 
+// Arguments passed to |DidRedirectNavigation|.
+struct TestDidRedirectNavigationInfo {
+  TestDidRedirectNavigationInfo();
+  ~TestDidRedirectNavigationInfo();
+  WebState* web_state = nullptr;
+  std::unique_ptr<web::NavigationContext> context;
+};
+
 // Arguments passed to |DidFinishNavigation|.
 struct TestDidFinishNavigationInfo {
   TestDidFinishNavigationInfo();
@@ -43,16 +51,31 @@ struct TestDidFinishNavigationInfo {
   std::unique_ptr<web::NavigationContext> context;
 };
 
+// Arguments passed to |DidStartLoading|.
+struct TestStartLoadingInfo {
+  WebState* web_state = nullptr;
+};
+
+// Arguments passed to |DidStopLoading|.
+struct TestStopLoadingInfo {
+  WebState* web_state = nullptr;
+};
+
 // Arguments passed to |PageLoaded|.
 struct TestLoadPageInfo {
   WebState* web_state = nullptr;
-  bool success;
+  bool success = false;
 };
 
 // Arguments passed to |LoadProgressChanged|.
 struct TestChangeLoadingProgressInfo {
   WebState* web_state = nullptr;
-  double progress;
+  double progress = 0.0;
+};
+
+// Arguments passed to |DidChangeBackForwardState|.
+struct TestDidChangeBackForwardStateInfo {
+  WebState* web_state = nullptr;
 };
 
 // Arguments passed to |TitleWasSet|.
@@ -92,18 +115,13 @@ struct TestRenderProcessGoneInfo {
   WebState* web_state = nullptr;
 };
 
-// Arguments passed to |WebStateDestroyed|.
-struct TestWebStateDestroyedInfo {
-  WebState* web_state = nullptr;
-};
-
-// Arguments passed to |DidStartLoading|.
-struct TestStartLoadingInfo {
+// Arguments passed to |WebStateRealized|.
+struct TestWebStateRealizedInfo {
   WebState* web_state = nullptr;
 };
 
-// Arguments passed to |DidStopLoading|.
-struct TestStopLoadingInfo {
+// Arguments passed to |WebStateDestroyed|.
+struct TestWebStateDestroyedInfo {
   WebState* web_state = nullptr;
 };
 

ios/web/public/test/fakes/fake_web_state_observer_util.mm

@@ -12,12 +12,18 @@
 #endif
 
 namespace web {
-TestDidChangeVisibleSecurityStateInfo::TestDidChangeVisibleSecurityStateInfo() {
-}
+TestDidChangeVisibleSecurityStateInfo::TestDidChangeVisibleSecurityStateInfo() =
+    default;
 TestDidChangeVisibleSecurityStateInfo::
-    ~TestDidChangeVisibleSecurityStateInfo() {}
-TestDidStartNavigationInfo::TestDidStartNavigationInfo() {}
+    ~TestDidChangeVisibleSecurityStateInfo() = default;
+TestDidStartNavigationInfo::TestDidStartNavigationInfo() = default;
 TestDidStartNavigationInfo::~TestDidStartNavigationInfo() = default;
-TestDidFinishNavigationInfo::TestDidFinishNavigationInfo() {}
+TestDidRedirectNavigationInfo::TestDidRedirectNavigationInfo() = default;
+TestDidRedirectNavigationInfo::~TestDidRedirectNavigationInfo() = default;
+TestDidFinishNavigationInfo::TestDidFinishNavigationInfo() = default;
 TestDidFinishNavigationInfo::~TestDidFinishNavigationInfo() = default;
+TestUpdateFaviconUrlCandidatesInfo::TestUpdateFaviconUrlCandidatesInfo() =
+    default;
+TestUpdateFaviconUrlCandidatesInfo::~TestUpdateFaviconUrlCandidatesInfo() =
+    default;
 }  // namespace web

ios/web/public/web_state.h

@@ -182,6 +182,39 @@ class WebState : public base::SupportsUserData {
   virtual WebStateDelegate* GetDelegate() = 0;
   virtual void SetDelegate(WebStateDelegate* delegate) = 0;
 
+  // Returns whether the WebState is realized.
+  //
+  // What does "realized" mean? When creating a WebState from session storage
+  // with |CreateWithStorageSession()|, it may not yet have been fully created.
+  // Instead, it has all information to fully instantiate it and its history
+  // available, but the underlying objects (WKWebView, NavigationManager, ...)
+  // have not been created.
+  //
+  // This is an optimisation to reduce the amount of memory consumed by tabs
+  // that have been restored after the browser has been shutdown. If the user
+  // has many tabs, but only consult a subset of them, then there is no point
+  // in creating them eagerly at startup. Instead, the creation is delayed
+  // until the tabs are activated by the user.
+  //
+  // When the WebState becomes realized, the WebStateRealized() event will be
+  // sent to all its WebStateObservers. They can listen to that event if they
+  // need to support this optimisation (by delaying the creation of their own
+  // state until the WebState is really used).
+  //
+  // See //docs/ios/unrealized_web_state.md for more information.
+  virtual bool IsRealized() const = 0;
+
+  // Forcefully bring the WebState in "realized" state. This method can safely
+  // be called multiple time on a WebState, though it should not be necessary
+  // to call it as the WebState will lazily switch to "realized" state when
+  // needed.
+  //
+  // Returns `this` so that the method can be chained such as:
+  //
+  //    WebState* web_state = ...;
+  //    web_state->ForceRealized()->SetDelegate(this);
+  virtual WebState* ForceRealized() = 0;
+
   // Whether or not a web view is allowed to exist in this WebState. Defaults
   // to false; this should be enabled before attempting to access the view.
   virtual bool IsWebUsageEnabled() const = 0;