[rendertext,i18n] Added flag to force RTL rendering

base/i18n/rtl.cc

Index: base/i18n/rtl.cc
diff --git a/base/i18n/rtl.cc b/base/i18n/rtl.cc
index 095d66c6d8af13a9846e70ddc4fdf650410d2d03..76a07730893514f579beacd2e8a0c42dcdb88dd8 100644
--- a/base/i18n/rtl.cc
+++ b/base/i18n/rtl.cc
@@ -51,10 +51,26 @@ std::string GetLocaleString(const icu::Locale& locale) {
   return result;
 }
 
+bool HasForcedTextDirectionSwitch() {

[msw, 2017/05/01 20:56:18]

nit: "// Get the cached switch presence; avoids repeated lookup in the common
case." (or you can inline this static bool in the function below)

[Kevin Bailey, 2017/05/01 21:21:42]

Done. Seemed like a bit much overhead for a whole function.

+  static bool value = base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kForceTextDirection);
+  return value;
+}
+
 // Returns LEFT_TO_RIGHT or RIGHT_TO_LEFT if |character| has strong
 // directionality, returns UNKNOWN_DIRECTION if it doesn't. Please refer to
 // http://unicode.org/reports/tr9/ for more information.
 base::i18n::TextDirection GetCharacterDirection(UChar32 character) {
+  if (HasForcedTextDirectionSwitch()) {
+    base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+    std::string force_flag =
+        command_line->GetSwitchValueASCII(switches::kForceTextDirection);
+
+    if (force_flag == switches::kForceDirectionRTL)
+      return base::i18n::RIGHT_TO_LEFT;
+    if (force_flag == switches::kForceDirectionLTR)
+      return base::i18n::LEFT_TO_RIGHT;
+  }
   // Now that we have the character, we use ICU in order to query for the
   // appropriate Unicode BiDi character type.
   int32_t property = u_getIntPropertyValue(character, UCHAR_BIDI_CLASS);
@@ -85,10 +101,10 @@ base::i18n::TextDirection GetForcedTextDirection() {
     std::string force_flag =
         command_line->GetSwitchValueASCII(switches::kForceUIDirection);
 
-    if (force_flag == switches::kForceUIDirectionLTR)
+    if (force_flag == switches::kForceDirectionLTR)
       return base::i18n::LEFT_TO_RIGHT;
 
-    if (force_flag == switches::kForceUIDirectionRTL)
+    if (force_flag == switches::kForceDirectionRTL)
       return base::i18n::RIGHT_TO_LEFT;
   }