[Telemetry] Support downloading profiles from cloud storage

tools/telemetry/telemetry/core/browser_finder.py

Index: tools/telemetry/telemetry/core/browser_finder.py
diff --git a/tools/telemetry/telemetry/core/browser_finder.py b/tools/telemetry/telemetry/core/browser_finder.py
index 66bf22e5e291d2e8d382487faec0b67c10218242..3c94c0f4fc7dc28417ed52876b2daca3770ba360 100644
--- a/tools/telemetry/telemetry/core/browser_finder.py
+++ b/tools/telemetry/telemetry/core/browser_finder.py
@@ -6,6 +6,7 @@
 
 import logging
 import operator
+import sys
 
 from telemetry.core.backends.webdriver import webdriver_desktop_browser_finder
 from telemetry.core.backends.chrome import android_browser_finder
@@ -30,6 +31,25 @@ class BrowserTypeRequiredException(Exception):
 class BrowserFinderException(Exception):
   pass
 
+def TargetBrowserOS(options):

[jeremy, 2014/01/06 06:57:07]

Guessing that we want a more robust version of this, one option would be to
perform most of FindBrowser() here to resolve the browser object and then cache
it to pass it back in FindBrowser?

In addition to the above, we'd probably want Browser objects to have a method
returning their Target OS.

WDYT?

[aberent, 2014/01/06 10:44:52]

How difficult would it be to create the robust version immediately? Also could
the robust version simply call FindBrowser() and then ask the resulting browser
what the OS is?

[jeremy, 2014/01/06 11:23:58]

Yes, was mainly looking for feedback before I make further changes here.

Per off-line discussion I plan to call FindBrowser() here and cache the value,
then add a static method to the Browser class to return the target OS.

The only extra bit is an assertion in FindBrowser to make sure that any later
calls have the same value for the --browser command line variable.

+  """ Return the OS of the target that the browser will run on.
+
+  TODO(jeremy):
+  This function is meant to run before FindBrowser() which performs the final
+  resolution of target OS.  Under certain circumstances e.g. browser_type=any
+  the value returned by this function may be incorrect.
+
+  Returns:
+    String indicating target OS.
+  """
+  browser_type = options.browser_type
+  if browser_type and browser_type.startswith('cros'):
+    return 'cros'
+  elif browser_type and browser_type.startswith('android'):
+    return 'android'
+
+  return sys.platform.lower()
+
 
 def FindBrowser(options):
   """Finds the best PossibleBrowser object given a BrowserOptions object.