Navigation: Convert BeginNavigation to a mojo method

- Replace the old BeginNavigation IPC by the equivalent mojo call in
the FrameHost interface. Removed all reference to the old IPC and the
render_frame_host callback.

- Convert BeginNavigationParams to a mojo structure. Most of this patch
is simply modifying function prototypes to match the new mojo syntax.

Bug: 784904
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_site_isolation
Change-Id: I6f288c1d44c6dd7ab34726689ebf241ae45f73de
Reviewed-on: https://chromium-review.googlesource.com/763529
Reviewed-by: Daniel Cheng <[email protected]>
Reviewed-by: Camille Lamy <[email protected]>
Commit-Queue: Arthur Hemery <[email protected]>
Cr-Commit-Position: refs/heads/master@{#520943}
diff --git a/content/common/frame.mojom b/content/common/frame.mojom
index 10c3996..8ae578c 100644
--- a/content/common/frame.mojom
+++ b/content/common/frame.mojom
@@ -4,6 +4,7 @@
 
 module content.mojom;
 
+import "content/common/navigation_params.mojom";
 import "content/common/url_loader_factory_bundle.mojom";
 import "content/public/common/url_loader.mojom";
 import "content/public/common/window_container_type.mojom";
@@ -170,4 +171,10 @@
   // Sent by the renderer when a navigation commits in the frame.
   DidCommitProvisionalLoad(
       DidCommitProvisionalLoadParams params);
+
+  // Sent by the renderer to request a navigation.
+  BeginNavigation(
+      CommonNavigationParams common_params,
+      BeginNavigationParams begin_params);
 };
+