Revert of Tab/Desktop Capture: Use requests instead of timer-based refreshing.

media/capture/content/video_capture_oracle_unittest.cc

 // Copyright (c) 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/capture/content/video_capture_oracle.h"
 
 #include "base/strings/stringprintf.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace media {
@@ skipping 180 matching lines @@
       // delta between frame timestamps should never be more than 2X the
       // |event_increment|.
       const base::TimeDelta max_acceptable_delta =
           (i % 100) == 78 ? event_increment * 5 : event_increment * 2;
       EXPECT_GE(max_acceptable_delta.InMicroseconds(), delta.InMicroseconds());
     }
     last_frame_timestamp = frame_timestamp;
   }
 }
 
-// Tests that VideoCaptureOracle prevents refresh request events from initiating
+// Tests that VideoCaptureOracle prevents timer polling from initiating
 // simultaneous captures.
-TEST(VideoCaptureOracleTest, SamplesAtCorrectTimesAroundRefreshRequests) {
+TEST(VideoCaptureOracleTest, SamplesOnlyOneOverdueFrameAtATime) {
   const base::TimeDelta vsync_interval = base::TimeDelta::FromSeconds(1) / 60;
-  const base::TimeDelta refresh_interval =
-      base::TimeDelta::FromMilliseconds(125);  // 8 FPS
+  const base::TimeDelta timer_interval = base::TimeDelta::FromMilliseconds(
+      VideoCaptureOracle::kMinTimerPollPeriodMillis);
 
   VideoCaptureOracle oracle(Get30HzPeriod(), Get720pSize(),
                             media::RESOLUTION_POLICY_FIXED_RESOLUTION, false);
 
   // Have the oracle observe some compositor events.  Simulate that each capture
   // completes successfully.
   base::TimeTicks t = InitialTestTimeTicks();
   base::TimeTicks ignored;
   bool did_complete_a_capture = false;
   for (int i = 0; i < 10; ++i) {
@@ skipping 12 matching lines @@
   for (int i = 0; i <= 10; ++i) {
     ASSERT_GT(10, i) << "BUG: Seems like it'll never happen!";
     t += vsync_interval;
     if (oracle.ObserveEventAndDecideCapture(
             VideoCaptureOracle::kCompositorUpdate, gfx::Rect(), t)) {
       break;
     }
   }
   int frame_number = oracle.RecordCapture(0.0);
 
-  // Stop providing the compositor events and start providing refresh request
+  // Stop providing the compositor events and start providing timer polling
   // events.  No overdue samplings should be recommended because of the
   // not-yet-complete compositor-based capture.
   for (int i = 0; i < 10; ++i) {
-    t += refresh_interval;
+    t += timer_interval;
     ASSERT_FALSE(oracle.ObserveEventAndDecideCapture(
-        VideoCaptureOracle::kPassiveRefreshRequest, gfx::Rect(), t));
+        VideoCaptureOracle::kTimerPoll, gfx::Rect(), t));
   }
 
   // Now, complete the oustanding compositor-based capture and continue
-  // providing refresh request events.  The oracle should start recommending
+  // providing timer polling events.  The oracle should start recommending
   // sampling again.
   ASSERT_TRUE(oracle.CompleteCapture(frame_number, true, &ignored));
   did_complete_a_capture = false;
   for (int i = 0; i < 10; ++i) {
-    t += refresh_interval;
-    if (oracle.ObserveEventAndDecideCapture(
-            VideoCaptureOracle::kPassiveRefreshRequest, gfx::Rect(), t)) {
+    t += timer_interval;
+    if (oracle.ObserveEventAndDecideCapture(VideoCaptureOracle::kTimerPoll,
+                                            gfx::Rect(), t)) {
       ASSERT_TRUE(
           oracle.CompleteCapture(oracle.RecordCapture(0.0), true, &ignored));
       did_complete_a_capture = true;
     }
   }
   ASSERT_TRUE(did_complete_a_capture);
 
-  // Start one more "refresh" capture, but do not notify of completion yet.
+  // Start one more timer-based capture, but do not notify of completion yet.
   for (int i = 0; i <= 10; ++i) {
     ASSERT_GT(10, i) << "BUG: Seems like it'll never happen!";
-    t += refresh_interval;
-    if (oracle.ObserveEventAndDecideCapture(
-            VideoCaptureOracle::kPassiveRefreshRequest, gfx::Rect(), t)) {
+    t += timer_interval;
+    if (oracle.ObserveEventAndDecideCapture(VideoCaptureOracle::kTimerPoll,
+                                            gfx::Rect(), t)) {
       break;
     }
   }
   frame_number = oracle.RecordCapture(0.0);
 
   // Confirm that the oracle does not recommend sampling until the outstanding
-  // "refresh" capture completes.
+  // timer-based capture completes.
   for (int i = 0; i < 10; ++i) {
-    t += refresh_interval;
+    t += timer_interval;
     ASSERT_FALSE(oracle.ObserveEventAndDecideCapture(
-        VideoCaptureOracle::kPassiveRefreshRequest, gfx::Rect(), t));
+        VideoCaptureOracle::kTimerPoll, gfx::Rect(), t));
   }
   ASSERT_TRUE(oracle.CompleteCapture(frame_number, true, &ignored));
   for (int i = 0; i <= 10; ++i) {
     ASSERT_GT(10, i) << "BUG: Seems like it'll never happen!";
-    t += refresh_interval;
-    if (oracle.ObserveEventAndDecideCapture(
-            VideoCaptureOracle::kPassiveRefreshRequest, gfx::Rect(), t)) {
+    t += timer_interval;
+    if (oracle.ObserveEventAndDecideCapture(VideoCaptureOracle::kTimerPoll,
+                                            gfx::Rect(), t)) {
       break;
     }
   }
 }
 
 // Tests that VideoCaptureOracle does not rapidly change proposed capture sizes,
 // to allow both the source content and the rest of the end-to-end system to
 // stabilize.
 TEST(VideoCaptureOracleTest, DoesNotRapidlyChangeCaptureSize) {
   VideoCaptureOracle oracle(Get30HzPeriod(), Get720pSize(),
@@ skipping 312 matching lines @@
     ASSERT_TRUE(oracle.ObserveEventAndDecideCapture(
         VideoCaptureOracle::kCompositorUpdate, gfx::Rect(), t));
     ASSERT_EQ(Get720pSize(), oracle.capture_size());
     base::TimeTicks ignored;
     ASSERT_TRUE(
         oracle.CompleteCapture(oracle.RecordCapture(2.0), true, &ignored));
   }
 }
 
 }  // namespace media