Bug 1444430 - Add a profiler feature called "screenshots". r=njn

MozReview-Commit-ID: 8blNvvliuog

--HG--
extra : rebase_source : 5465eb074f3988f9f3de9e00e1c42ce7897112c9

browser/components/extensions/schemas/geckoProfiler.json

@@ -30,6 +30,7 @@
           "memory",
           "privacy",
           "restyle",
+          "screenshots",
           "stackwalk",
           "tasktracer",
           "threads",

devtools/server/tests/browser/browser_perf-04.js

@@ -20,7 +20,7 @@ add_task(async function() {
   front.once("profiler-started", (entries, interval, features) => {
     is(entries, 1000, "Should apply entries by startProfiler");
     is(interval, 0.1, "Should apply interval by startProfiler");
-    is(features, 0x82, "Should apply features by startProfiler");
+    is(features, 0x102, "Should apply features by startProfiler");
   });
 
   // Start the profiler.

tools/profiler/public/GeckoProfiler.h

@@ -121,17 +121,20 @@ class TimeStamp;
   /* Restyle profiling. */ \
   macro(6, "restyle", Restyle) \
   \
+  /* Take a snapshot of the window on every composition. */ \
+  macro(7, "screenshots", Screenshots) \
+  \
   /* Walk the C++ stack. Not available on all platforms. */ \
-  macro(7, "stackwalk", StackWalk) \
+  macro(8, "stackwalk", StackWalk) \
   \
   /* Start profiling with feature TaskTracer. */ \
-  macro(8, "tasktracer", TaskTracer) \
+  macro(9, "tasktracer", TaskTracer) \
   \
   /* Profile the registered secondary threads. */ \
-  macro(9, "threads", Threads) \
+  macro(10, "threads", Threads) \
   \
   /* Have the JavaScript engine track JIT optimizations. */ \
-  macro(10, "trackopts", TrackOptimizations)
+  macro(11, "trackopts", TrackOptimizations)
 
 struct ProfilerFeature
 {