[PM] Rename WebMemoryAggregator to WebMemoryMeasurer

This class manages the memory request but does not actually do the
aggregation. crrev.com/c/2557730 will add another class that does the
aggregation after the response is received.

The unit tests are still named WebMemoryAggregator because they will
also test the new aggregator class which will be invoked by
WebMemoryMeasurer.

Bug: 1085129
Change-Id: I21a13a407cb96d720463e4d5b009098156324294
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2569675Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Commit-Queue: Joe Mason <joenotcharles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833341}

components/performance_manager/v8_memory/web_memory_aggregator.cc

@@ -84,23 +84,22 @@ void WebMeasureMemory(
     const FrameNode* frame_node,
     mojom::WebMemoryMeasurement::Mode mode,
     base::OnceCallback<void(mojom::WebMemoryMeasurementPtr)> callback) {
-  auto web_memory_aggregator = std::make_unique<WebMemoryAggregator>(
+  auto measurer = std::make_unique<WebMemoryMeasurer>(
       frame_node->GetFrameToken(),
       WebMeasurementModeToRequestMeasurementMode(mode), std::move(callback));
 
-  // Create a measurement complete callback to own |web_memory_aggregator|. It
+  // Create a measurement complete callback to own |measurer|. It
   // will be deleted when the callback is executed or dropped.
-  V8DetailedMemoryRequestOneShot* request = web_memory_aggregator->request();
-  auto measurement_complete_callback =
-      base::BindOnce(&WebMemoryAggregator::MeasurementComplete,
-                     std::move(web_memory_aggregator));
+  V8DetailedMemoryRequestOneShot* request = measurer->request();
+  auto measurement_complete_callback = base::BindOnce(
+      &WebMemoryMeasurer::MeasurementComplete, std::move(measurer));
 
   // Start memory measurement for the process of the given frame.
   request->StartMeasurement(frame_node->GetProcessNode(),
                             std::move(measurement_complete_callback));
 }
 
-WebMemoryAggregator::WebMemoryAggregator(
+WebMemoryMeasurer::WebMemoryMeasurer(
     const blink::LocalFrameToken& frame_token,
     V8DetailedMemoryRequest::MeasurementMode mode,
     MeasurementCallback callback)
@@ -108,9 +107,9 @@ WebMemoryAggregator::WebMemoryAggregator(
       callback_(std::move(callback)),
       request_(std::make_unique<V8DetailedMemoryRequestOneShot>(mode)) {}
 
-WebMemoryAggregator::~WebMemoryAggregator() = default;
+WebMemoryMeasurer::~WebMemoryMeasurer() = default;
 
-void WebMemoryAggregator::MeasurementComplete(
+void WebMemoryMeasurer::MeasurementComplete(
     const ProcessNode* process_node,
     const V8DetailedMemoryProcessData*) {
   std::move(callback_).Run(BuildMemoryUsageResult(frame_token_, process_node));

components/performance_manager/v8_memory/web_memory_aggregator.h

@@ -18,17 +18,19 @@ class ProcessNode;
 
 namespace v8_memory {
 
-// A helper class for implementing WebMeasureMemory().
-class WebMemoryAggregator {
+// A helper class for implementing WebMeasureMemory(). This manages a request
+// object that sends a V8 detailed memory request to the renderer, and formats
+// the result into a mojom::WebMemoryMeasurement.
+class WebMemoryMeasurer {
  public:
   using MeasurementCallback =
       base::OnceCallback<void(mojom::WebMemoryMeasurementPtr)>;
 
-  WebMemoryAggregator(const blink::LocalFrameToken&,
-                      V8DetailedMemoryRequest::MeasurementMode,
-                      MeasurementCallback);
+  WebMemoryMeasurer(const blink::LocalFrameToken&,
+                    V8DetailedMemoryRequest::MeasurementMode,
+                    MeasurementCallback);
 
-  ~WebMemoryAggregator();
+  ~WebMemoryMeasurer();
 
   V8DetailedMemoryRequestOneShot* request() const { return request_.get(); }
 

components/performance_manager/v8_memory/web_memory_aggregator_unittest.cc

@@ -100,7 +100,7 @@ void WebMemoryAggregatorTest::MeasureAndVerify(
     FrameNodeImpl* frame,
     base::flat_map<std::string, Bytes> expected) {
   bool measurement_done = false;
-  WebMemoryAggregator web_memory(
+  WebMemoryMeasurer web_memory(
       frame->frame_token(), V8DetailedMemoryRequest::MeasurementMode::kDefault,
       base::BindLambdaForTesting([&measurement_done, &expected](
                                      mojom::WebMemoryMeasurementPtr result) {