V8 per-frame memory, get isolated world and host IDs for each context.

Bug: 998546
Change-Id: I1a356768fad7914992631ce1d740029c8f61d39c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2213885Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Joe Mason <joenotcharles@chromium.org>
Commit-Queue: Sigurður Ásgeirsson <siggi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772313}

chrome/renderer/performance_manager/decorators/v8_per_frame_memory_reporter_impl.cc

@@ -5,6 +5,7 @@
 #include "chrome/renderer/performance_manager/decorators/v8_per_frame_memory_reporter_impl.h"
 
 #include "content/public/common/isolated_world_ids.h"
+#include "extensions/renderer/script_injection.h"
 #include "mojo/public/cpp/bindings/self_owned_receiver.h"
 #include "third_party/blink/public/web/web_local_frame.h"
 #include "third_party/blink/public/web/web_local_frame_client.h"
@@ -51,11 +52,7 @@ class FrameAssociatedMeasurementDelegate : public v8::MeasureMemoryDelegate {
       blink::WebLocalFrame* frame =
           blink::WebLocalFrame::FrameForContext(context);
 
-      // TODO(siggi): Expose a way to get the WorldId for a context in
-      //     blink/public somewhere. The WorldId is already exposed at that
-      //     level except only in the WebLocalFrameClient callbacks.
-      //     From the WorldId it's then possible to resolve the host ID.
-      if (!frame || context != frame->MainWorldScriptContext()) {
+      if (!frame) {
         // TODO(siggi): It would be prefereable to count the V8SchemaRegistry
         //     context's overhead with unassociated_bytes, but at present there
         //     isn't a public API that allows this distinction.
@@ -63,18 +60,25 @@ class FrameAssociatedMeasurementDelegate : public v8::MeasureMemoryDelegate {
         result->unassociated_context_bytes_used += size;
       } else {
         base::UnguessableToken token = frame->Client()->GetDevToolsFrameToken();
-        DCHECK(!base::Contains(result->associated_memory, token));
+
+        mojom::PerFrameV8MemoryUsageData* per_frame_resources =
+            result->associated_memory[token].get();
+        if (!per_frame_resources) {
+          auto new_resources = mojom::PerFrameV8MemoryUsageData::New();
+          per_frame_resources = new_resources.get();
+          result->associated_memory[token] = std::move(new_resources);
+        }
 
         mojom::V8IsolatedWorldMemoryUsagePtr isolated_world_usage =
             mojom::V8IsolatedWorldMemoryUsage::New();
         isolated_world_usage->bytes_used = size;
-        mojom::PerFrameV8MemoryUsageDataPtr per_frame_resources =
-            mojom::PerFrameV8MemoryUsageData::New();
-        per_frame_resources
-            ->associated_bytes[content::ISOLATED_WORLD_ID_GLOBAL] =
+        int32_t world_id = frame->GetScriptContextWorldId(context);
+        isolated_world_usage->host_id =
+            extensions::ScriptInjection::GetHostIdForIsolatedWorld(world_id);
+        DCHECK(
+            !base::Contains(per_frame_resources->associated_bytes, world_id));
+        per_frame_resources->associated_bytes[world_id] =
             std::move(isolated_world_usage);
-
-        result->associated_memory[token] = std::move(per_frame_resources);
       }
     }
 

third_party/blink/public/web/web_local_frame.h

@@ -337,6 +337,10 @@ class WebLocalFrame : public WebFrame {
   // be calling this API.
   virtual v8::Local<v8::Context> MainWorldScriptContext() const = 0;
 
+  // Returns the world ID associated with |script_context|.
+  virtual int32_t GetScriptContextWorldId(
+      v8::Local<v8::Context> script_context) const = 0;
+
   // Executes script in the context of the current page and returns the value
   // that the script evaluated to with callback. Script execution can be
   // suspend.

third_party/blink/renderer/core/exported/web_frame_test.cc

@@ -4567,6 +4567,11 @@ TEST_F(WebFrameTest, ContextNotificationsIsolatedWorlds) {
   ASSERT_NE(web_view_helper.LocalMainFrame()->MainWorldScriptContext(),
             v8::Local<v8::Context>::New(isolate, notification->context));
 
+  // Check that the context we got has the right isolated world id.
+  ASSERT_EQ(isolated_world_id,
+            web_view_helper.LocalMainFrame()->GetScriptContextWorldId(
+                v8::Local<v8::Context>::New(isolate, notification->context)));
+
   web_view_helper.Reset();
 
   // We should have gotten three release notifications (one for each of the

third_party/blink/renderer/core/frame/web_local_frame_impl.cc

@@ -941,6 +941,12 @@ v8::Local<v8::Context> WebLocalFrameImpl::MainWorldScriptContext() const {
   return script_state->GetContext();
 }
 
+int32_t WebLocalFrameImpl::GetScriptContextWorldId(
+    v8::Local<v8::Context> script_context) const {
+  DCHECK_EQ(this, FrameForContext(script_context));
+  return DOMWrapperWorld::World(script_context).GetWorldId();
+}
+
 v8::Local<v8::Object> WebLocalFrameImpl::GlobalProxy() const {
   return MainWorldScriptContext()->Global();
 }

third_party/blink/renderer/core/frame/web_local_frame_impl.h

@@ -159,6 +159,8 @@ class CORE_EXPORT WebLocalFrameImpl final
       int argc,
       v8::Local<v8::Value> argv[]) override;
   v8::Local<v8::Context> MainWorldScriptContext() const override;
+  int32_t GetScriptContextWorldId(
+      v8::Local<v8::Context> script_context) const override;
   void RequestExecuteScriptAndReturnValue(const WebScriptSource&,
                                           bool user_gesture,
                                           WebScriptExecutionCallback*) override;