[Remoting Mobile] Move the minimum portrait resolution checking logic to ChromotingSession

This CL moves the logic of ignoring client resolution of a portrait mode
phone screen into ChromotingSession, so that the Android client can get
this for free.

Bug: 874626
Change-Id: I0bf946c8a2ba5ce52e70b54b06517a3334f5727e
Reviewed-on: https://chromium-review.googlesource.com/1187802
Commit-Queue: Yuwei Huang <yuweih@chromium.org>
Reviewed-by: Joe Downing <joedow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586001}

remoting/client/chromoting_session.cc

@@ -55,6 +55,13 @@ const int kMinDimension = 640;
 // Interval at which to log performance statistics, if enabled.
 constexpr base::TimeDelta kPerfStatsInterval = base::TimeDelta::FromMinutes(1);
 
+bool IsClientResolutionValid(int dips_width, int dips_height) {
+  // This prevents sending resolution on a portrait mode small phone screen
+  // because resizing the remote desktop to portrait will mess with icons and
+  // such on the desktop and it probably isn't what the user wants.
+  return (dips_width >= dips_height) || (dips_width >= kMinDimension);
+}
+
 // Normalizes the resolution so that both dimensions are not smaller than
 // kMinDimension.
 void NormalizeClientResolution(protocol::ClientResolution* resolution) {
@@ -277,6 +284,10 @@ void ChromotingSession::Core::SendClientResolution(int dips_width,
                                                    int dips_height,
                                                    float scale) {
   DCHECK(network_task_runner()->BelongsToCurrentThread());
+  if (!IsClientResolutionValid(dips_width, dips_height)) {
+    return;
+  }
+
   protocol::ClientResolution client_resolution;
   client_resolution.set_dips_width(dips_width);
   client_resolution.set_dips_height(dips_height);

remoting/ios/app/host_view_controller.mm

@@ -407,14 +407,7 @@ static NSString* const kFeedbackContext = @"InSessionFeedbackContext";
 }
 
 - (void)resizeHostToFitIfNeeded {
-  // Don't adjust if it's the phone and in portrait orientation because UI looks
-  // too tight.
-  BOOL isPhonePortrait =
-      self.traitCollection.horizontalSizeClass ==
-          UIUserInterfaceSizeClassCompact &&
-      self.traitCollection.verticalSizeClass == UIUserInterfaceSizeClassRegular;
-
-  if (_settings.shouldResizeHostToFit && !isPhonePortrait) {
+  if (_settings.shouldResizeHostToFit) {
     UIEdgeInsets safeInsets = remoting::SafeAreaInsetsForView(_hostView);
     CGRect safeRect = UIEdgeInsetsInsetRect(_hostView.frame, safeInsets);
     [_client setHostResolution:safeRect.size