[Code health] Avoid Value::GetAsDictionary (in /content/browser)

This method is deprecated, so port away from it, along with other nearby deprecated base::Value APIs that can be modernized at least somewhat locally.

This CL was uploaded by git cl split.

R=kenrb@chromium.org

Bug: 1187011
Change-Id: I0bc940754a9254c1d9f3d3d4a0b16a599999f02d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3827421
Auto-Submit: Maks Orlovich <morlovich@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Commit-Queue: Ken Buchanan <kenrb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1034943}

content/browser/site_per_process_hit_test_browsertest.cc

@@ -644,14 +644,14 @@ void HitTestRootWindowTransform(
 
 #if defined(USE_AURA)
 bool ConvertJSONToPoint(const std::string& str, gfx::PointF* point) {
-  std::unique_ptr<base::Value> value = base::JSONReader::ReadDeprecated(str);
+  absl::optional<base::Value> value = base::JSONReader::Read(str);
   if (!value)
     return false;
-  base::DictionaryValue* root;
-  if (!value->GetAsDictionary(&root))
+  base::Value::Dict* root = value->GetIfDict();
+  if (!root)
     return false;
-  absl::optional<double> x = root->FindDoubleKey("x");
-  absl::optional<double> y = root->FindDoubleKey("y");
+  absl::optional<double> x = root->FindDouble("x");
+  absl::optional<double> y = root->FindDouble("y");
   if (!x || !y)
     return false;
   point->set_x(*x);
@@ -660,22 +660,22 @@ bool ConvertJSONToPoint(const std::string& str, gfx::PointF* point) {
 }
 
 bool ConvertJSONToRect(const std::string& str, gfx::Rect* rect) {
-  std::unique_ptr<base::Value> value = base::JSONReader::ReadDeprecated(str);
+  absl::optional<base::Value> value = base::JSONReader::Read(str);
   if (!value)
     return false;
-  base::DictionaryValue* root;
-  if (!value->GetAsDictionary(&root))
+  base::Value::Dict* root = value->GetIfDict();
+  if (!root)
     return false;
-  absl::optional<int> x = root->FindIntKey("x");
+  absl::optional<int> x = root->FindInt("x");
   if (!x)
     return false;
-  absl::optional<int> y = root->FindIntKey("y");
+  absl::optional<int> y = root->FindInt("y");
   if (!y)
     return false;
-  absl::optional<int> width = root->FindIntKey("width");
+  absl::optional<int> width = root->FindInt("width");
   if (!width)
     return false;
-  absl::optional<int> height = root->FindIntKey("height");
+  absl::optional<int> height = root->FindInt("height");
   if (!height)
     return false;
   rect->set_x(*x);