refactor: use v8 serialization for ipc (#20214)

* refactor: use v8 serialization for ipc

* cloning process.env doesn't work

* serialize host objects by enumerating key/values

* new serialization can handle NaN, Infinity, and undefined correctly

* can't allocate v8 objects during GC

* backport microtasks fix

* fix compile

* fix node_stream_loader reentrancy

* update subframe spec to expect undefined instead of null

* write undefined instead of crashing when serializing host objects

* fix webview spec

* fix download spec

* buffers are transformed into uint8arrays

* can't serialize promises

* fix chrome.i18n.getMessage

* fix devtools tests

* fix zoom test

* fix debug build

* fix lint

* update ipcRenderer tests

* fix printToPDF test

* update patch

* remove accidentally re-added remote-side spec

* wip

* don't attempt to serialize host objects

* jump through different hoops to set options.webContents sometimes

* whoops

* fix lint

* clean up error-handling logic

* fix memory leak

* fix lint

* convert host objects using old base::Value serialization

* fix lint more

* fall back to base::Value-based serialization

* remove commented-out code

* add docs to breaking-changes.md

* Update breaking-changes.md

* update ipcRenderer and WebContents docs

* lint

* use named values for format tag

* save a memcpy for ~30% speedup

* get rid of calls to ShallowClone

* extra debugging for paranoia

* d'oh, use the correct named tags

* apparently msstl doesn't like this DCHECK

* funny story about that DCHECK

* disable remote-related functions when enable_remote_module = false

* nits

* use EnableIf to disable remote methods in mojom

* fix include

* review comments

shell/common/api/BUILD.gn

@@ -1,4 +1,5 @@
 import("//mojo/public/tools/bindings/mojom.gni")
+import("../../../buildflags/buildflags.gni")
 
 mojom("mojo") {
   sources = [
@@ -7,6 +8,12 @@ mojom("mojo") {
 
   public_deps = [
     "//mojo/public/mojom/base",
+    "//third_party/blink/public/mojom:mojom_core",
     "//ui/gfx/geometry/mojom",
   ]
+
+  enabled_features = []
+  if (enable_remote_module) {
+    enabled_features += [ "enable_remote_module" ]
+  }
 }