[CCA] Change preferred fps range for photo and video preview.

Preferred default fps range for photo mode preview. Preferred maximal
constant fps for video mode preview.

Bug: 976602
Test: Verify the fps range chosen by CCA in both video mode and photo
mode are correct.

Change-Id: Iefe209fe4596d69d29a135ebdc246de04e148015
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1861435
Auto-Submit: Kuo Jen Wei <inker@chromium.org>
Reviewed-by: Shik Chen <shik@chromium.org>
Commit-Queue: Kuo Jen Wei <inker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705883}

chrome/browser/resources/chromeos/camera/src/js/device/constraints_preferrer.js

@@ -133,10 +133,10 @@ cca.device.VideoConstraintsPreferrer =
     super(resolBroker, doReconfigureStream);
 
     /**
-     * Object saving information of supported constant fps. Each of its key as
-     * device id and value as an object mapping from resolution to all constant
-     * fps options supported by that resolution.
-     * @type {!Object<string, Object<Array<number>, Array<number>>>}
+     * Object saving information of device supported constant fps. Each of its
+     * key as device id and value as an object mapping from resolution to all
+     * constant fps options supported by that resolution.
+     * @type {!Object<string, !Object<!Array<number>, !Array<number>>>}
      * @private
      */
     this.constFpsInfo_ = {};
@@ -238,12 +238,12 @@ cca.device.VideoConstraintsPreferrer =
       }
       this.prefResolution_[deviceId] = {width, height};
 
-      const constFpses = cca.device.SUPPORTED_CONSTANT_FPS.filter(
-          (fps) => !!fpsRanges.find(
-              ([minFps, maxFps]) => minFps === fps && maxFps === fps));
+      const constFpses =
+          fpsRanges.filter(([minFps, maxFps]) => minFps === maxFps)
+              .map(([fps]) => fps);
       const fpsInfo = {};
-      for (const r of Object.keys(videoMaxFps).map((r) => r.toString())) {
-        fpsInfo[r] = constFpses.filter((fps) => fps <= videoMaxFps[r]);
+      for (const [resolution, maxFps] of Object.entries(videoMaxFps)) {
+        fpsInfo[resolution] = constFpses.filter((fps) => fps <= maxFps);
       }
       this.constFpsInfo_[deviceId] = fpsInfo;
     });
@@ -263,11 +263,11 @@ cca.device.VideoConstraintsPreferrer =
     this.resolBroker_.notifyVideoPrefResolChange(deviceId, width, height);
 
     const fps = stream.getVideoTracks()[0].getSettings().frameRate;
-    const availableFpses = this.constFpsInfo_[deviceId][[width, height]];
-    if (availableFpses.includes(fps)) {
     this.setPreferredConstFps_(deviceId, width, height, fps);
-    }
-    cca.state.set('multi-fps', availableFpses.length > 1);
+    const supportedConstFpses =
+        this.constFpsInfo_[deviceId][[width, height]].filter(
+            (fps) => cca.device.SUPPORTED_CONSTANT_FPS.includes(fps));
+    cca.state.set('multi-fps', supportedConstFpses.length > 1);
   }
 
   /**
@@ -305,14 +305,21 @@ cca.device.VideoConstraintsPreferrer =
     // support multiple constant fps options. The resolution-fps tuple are
     // sorted by user preference of constant fps.
     const getFpses = (r) => {
-      let constFpses = [null];
-      if (this.constFpsInfo_[deviceId][r].includes(30)) {
-        if (this.constFpsInfo_[deviceId][r].includes(60)) {
+      let constFpses;
+      const constFpsInfo = this.constFpsInfo_[deviceId][r];
+      // The higher constant fps will be ignored if constant 30 and 60 presented
+      // due to currently lack of UI support for toggling it.
+      if (constFpsInfo.includes(30) && constFpsInfo.includes(60)) {
         const prefFps =
             this.prefFpses_[deviceId] && this.prefFpses_[deviceId][r] || 30;
         constFpses = prefFps == 30 ? [30, 60] : [60, 30];
       } else {
-          constFpses = [30];
+        constFpses = [null];
+        if (constFpsInfo.length > 0) {
+          const maxConstFps = Math.max(...constFpsInfo);
+          if (maxConstFps >= 30) {
+            constFpses.unshift(maxConstFps);
+          }
         }
       }
       return constFpses.map((fps) => [...r, fps]);
@@ -384,7 +391,6 @@ cca.device.PhotoResolPreferrer = class extends cca.device.ConstraintsPreferrer {
             (maxR, R) => (maxR[0] * maxR[1] < R[0] * R[1] ? R : maxR), [0, 0]);
       }
       this.prefResolution_[deviceId] = {width, height};
-      return [deviceId, width, height, photoResols];
     });
     cca.proxy.browserProxy.localStorageSet(
         {devicePhotoResolution: this.prefResolution_});
@@ -455,7 +461,6 @@ cca.device.PhotoResolPreferrer = class extends cca.device.ConstraintsPreferrer {
                                         audio: false,
                                         video: {
                                           deviceId: {exact: deviceId},
-                                          frameRate: {min: 24},
                                           width,
                                           height,
                                         },