Reland: Remove DCHECK_IMPLIES/CHECK_IMPLIES.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 623fd1679c52b25ea070f4fb974b3ecbe4f00856..5485ee706e7eeabb8246dbb6788fd44a549aadd4 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -644,14 +644,14 @@ void RenderFrameImpl::CreateFrame(
         replicated_state.sandbox_flags);
   }
   render_frame->SetWebFrame(web_frame);
-  CHECK_IMPLIES(parent_routing_id == MSG_ROUTING_NONE, !web_frame->parent());
+  CHECK(parent_routing_id != MSG_ROUTING_NONE || !web_frame->parent());
 
   WebFrame* opener = ResolveOpener(opener_routing_id, nullptr);
   web_frame->setOpener(opener);
 
   if (widget_params.routing_id != MSG_ROUTING_NONE) {
-    CHECK_IMPLIES(web_frame->parent(),
-                  SiteIsolationPolicy::AreCrossProcessFramesPossible());
+    CHECK(!web_frame->parent() ||
+          SiteIsolationPolicy::AreCrossProcessFramesPossible());
     render_frame->render_widget_ = RenderWidget::CreateForFrame(
         widget_params.routing_id, widget_params.hidden,
         render_frame->render_view_->screen_info(), compositor_deps, web_frame);
@@ -1256,8 +1256,7 @@ void RenderFrameImpl::OnSwapOut(
       SiteIsolationPolicy::IsSwappedOutStateForbidden();
 
   // This codepath should only be hit for subframes when in --site-per-process.
-  CHECK_IMPLIES(!is_main_frame_,
-                SiteIsolationPolicy::AreCrossProcessFramesPossible());
+  CHECK(is_main_frame_ || SiteIsolationPolicy::AreCrossProcessFramesPossible());
 
   // Only run unload if we're not swapped out yet, but send the ack either way.
   if (!is_swapped_out_) {
@@ -2677,7 +2676,7 @@ void RenderFrameImpl::didStartProvisionalLoad(blink::WebLocalFrame* frame,
   DocumentState* document_state = DocumentState::FromDataSource(ds);
 
   // We should only navigate to swappedout:// when is_swapped_out_ is true.
-  CHECK_IMPLIES(ds->request().url() == GURL(kSwappedOutURL), is_swapped_out_)
+  CHECK(ds->request().url() != GURL(kSwappedOutURL) || is_swapped_out_)
       << "Heard swappedout:// when not swapped out.";
 
   // Update the request time if WebKit has better knowledge of it.
@@ -2843,9 +2842,8 @@ void RenderFrameImpl::didCommitProvisionalLoad(
     // SendUpdateState and update page_id_ even in this case, so that
     // the current entry gets a state update and so that we don't send a
     // state update to the wrong entry when we swap back in.
-    DCHECK_IMPLIES(
-        navigation_state->common_params().should_replace_current_entry,
-        render_view_->history_list_length_ > 0);
+    DCHECK(!navigation_state->common_params().should_replace_current_entry ||
+           render_view_->history_list_length_ > 0);
     if (GetLoadingUrl() != GURL(kSwappedOutURL) &&
         !navigation_state->common_params().should_replace_current_entry) {
       // Advance our offset in session history, applying the length limit.
@@ -4008,7 +4006,7 @@ void RenderFrameImpl::WasShown() {
   // VisibilityState remain a page-level concept or move to frames?
   // The semantics of 'Show' might have to change here.
   // TODO(avi): This DCHECK is to track cleanup for https://crbug.com/545684
-  DCHECK_IMPLIES(IsMainFrame(), render_widget_.get() == render_view_.get())
+  DCHECK(!IsMainFrame() || render_widget_.get() == render_view_.get())
       << "The main render frame is no longer reusing the RenderView as its "
       << "RenderWidget!";
   if (render_widget_ && render_view_.get() != render_widget_.get()) {
@@ -5013,12 +5011,12 @@ void RenderFrameImpl::BeginNavigation(blink::WebURLRequest* request) {
             GetFetchCredentialsModeForWebURLRequest(*request));
   DCHECK(GetFetchRedirectModeForWebURLRequest(*request) ==
          FetchRedirectMode::MANUAL_MODE);
-  DCHECK_IMPLIES(!frame_->parent(),
-                 GetRequestContextFrameTypeForWebURLRequest(*request) ==
-                 REQUEST_CONTEXT_FRAME_TYPE_TOP_LEVEL);
-  DCHECK_IMPLIES(frame_->parent(),
-                 GetRequestContextFrameTypeForWebURLRequest(*request) ==
-                 REQUEST_CONTEXT_FRAME_TYPE_NESTED);
+  DCHECK(frame_->parent() ||
+         GetRequestContextFrameTypeForWebURLRequest(*request) ==
+             REQUEST_CONTEXT_FRAME_TYPE_TOP_LEVEL);
+  DCHECK(!frame_->parent() ||
+         GetRequestContextFrameTypeForWebURLRequest(*request) ==
+             REQUEST_CONTEXT_FRAME_TYPE_NESTED);
 
   Send(new FrameHostMsg_BeginNavigation(
       routing_id_,