Remove unused IPC variable on History navigation API.

Now that back/forward buttons processing is moved to the browser we can
remove the need for the extra IPC variable. All calls now are solely
from javascript.

BUG=705583

Change-Id: Iec303699cda252501c147c6fb9a310f259de6be7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1788230
Reviewed-by: Kinuko Yasuda <[email protected]>
Commit-Queue: Dave Tapuska <[email protected]>
Cr-Commit-Position: refs/heads/master@{#695143}
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 6ab3420..f921389 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -4837,8 +4837,7 @@
 
 void WebContentsImpl::OnGoToEntryAtOffset(RenderFrameHostImpl* source,
                                           int offset,
-                                          bool has_user_gesture,
-                                          bool from_script) {
+                                          bool has_user_gesture) {
   // Non-user initiated navigations coming from the renderer should be ignored
   // if there is an ongoing browser-initiated navigation.
   // See https://crbug.com/879965.
@@ -4856,11 +4855,7 @@
 
   // All frames are allowed to navigate the global history.
   if (!delegate_ || delegate_->OnGoToEntryOffset(offset)) {
-    // We only check sandboxed navigation permissions on navigations originating
-    // from scripts, and not mouse back buttons (from_script == false), which
-    // also use this path.
-    if (from_script &&
-        source->IsSandboxed(blink::WebSandboxFlags::kTopNavigation)) {
+    if (source->IsSandboxed(blink::WebSandboxFlags::kTopNavigation)) {
       // Keep track of whether this is a session history from a sandboxed iframe
       // with top level navigation disallowed.
       controller_.GoToOffsetInSandboxedFrame(offset,